prokaryotic initiation factor 2


Summary: The largest of the three prokaryotic initiation factors with a molecular size of approximately 80 kD. It functions in the transcription initiation process by promoting the binding of formylmethionine-tRNA to the P-site of the 30S ribosome and by preventing the incorrect binding of elongator tRNA to the translation initiation site.

Top Publications

  1. Cameron D, Thompson J, March P, Dahlberg A. Initiation factor IF2, thiostrepton and micrococcin prevent the binding of elongation factor G to the Escherichia coli ribosome. J Mol Biol. 2002;319:27-35 pubmed
    ..Micrococcin stimulates GTP hydrolysis by both factors. We show directly that these drugs act by destabilizing the interaction of EF-G with the ribosome, and provide evidence that they have similar effects on IF2. ..
  2. Milon P, Konevega A, Gualerzi C, Rodnina M. Kinetic checkpoint at a late step in translation initiation. Mol Cell. 2008;30:712-20 pubmed publisher
  3. Allen G, Zavialov A, Gursky R, Ehrenberg M, Frank J. The cryo-EM structure of a translation initiation complex from Escherichia coli. Cell. 2005;121:703-12 pubmed
    ..Additionally, we present evidence for the localization of IF1, IF3, one C-terminal domain of L7/L12, and the N-terminal domain of IF2 in the initiation complex. ..
  4. Steiner Mosonyi M, Creuzenet C, Keates R, Strub B, Mangroo D. The Pseudomonas aeruginosa initiation factor IF-2 is responsible for formylation-independent protein initiation in P. aeruginosa. J Biol Chem. 2004;279:52262-9 pubmed publisher
    ..Furthermore these findings give important clues to the basis for discriminating the initiator Met-tRNA by IF-2 and for the evolution of alternative mechanisms for discrimination...
  5. Myasnikov A, Marzi S, Simonetti A, Giuliodori A, Gualerzi C, Yusupova G, et al. Conformational transition of initiation factor 2 from the GTP- to GDP-bound state visualized on the ribosome. Nat Struct Mol Biol. 2005;12:1145-9 pubmed
    ..Our data also provide insights into the molecular mechanism guiding release of IF1 and IF3. ..
  6. Antoun A, Pavlov M, Lovmar M, Ehrenberg M. How initiation factors maximize the accuracy of tRNA selection in initiation of bacterial protein synthesis. Mol Cell. 2006;23:183-93 pubmed
    ..We suggest why IF1 is essential for E. coli, discuss the role of the G-C base pairs in the anticodon stem of some tRNAs, and clarify gene expression changes with varying IF3 concentration in the living cell. ..
  7. Takahashi S, Detrick S, Whiting A, Blaschke Bonkowksy A, Aoyagi Y, Adderson E, et al. Correlation of phylogenetic lineages of group B Streptococci, identified by analysis of restriction-digestion patterns of genomic DNA, with infB alleles and mobile genetic elements. J Infect Dis. 2002;186:1034-8 pubmed
    ..These molecular markers can be used to identify GBS populations and to correlate RDP types and phylogenetic lineages identified by different methods. ..
  8. Grill S, Moll I, Hasenöhrl D, Gualerzi C, Blasi U. Modulation of ribosomal recruitment to 5'-terminal start codons by translation initiation factors IF2 and IF3. FEBS Lett. 2001;495:167-71 pubmed
  9. Grill S, Gualerzi C, Londei P, Blasi U. Selective stimulation of translation of leaderless mRNA by initiation factor 2: evolutionary implications for translation. EMBO J. 2000;19:4101-10 pubmed

More Information


  1. Grigoriadou C, Marzi S, Pan D, Gualerzi C, Cooperman B. The translational fidelity function of IF3 during transition from the 30 S initiation complex to the 70 S initiation complex. J Mol Biol. 2007;373:551-61 pubmed
  2. Mangroo D, RajBhandary U. Mutants of Escherichia coli initiator tRNA defective in initiation. Effects of overproduction of methionyl-tRNA transformylase and the initiation factors IF2 and IF3. J Biol Chem. 1995;270:12203-9 pubmed
    ..mRNA.fMet-tRNA initiation complex in Escherichia coli. Over-production of IF3 did not affect the initiator activity of any of the tRNA mutants studied. ..
  3. Guillon J, Heiss S, Soutourina J, Mechulam Y, Laalami S, Grunberg Manago M, et al. Interplay of methionine tRNAs with translation elongation factor Tu and translation initiation factor 2 in Escherichia coli. J Biol Chem. 1996;271:22321-5 pubmed
    ..M., Mechulam, Y., Schmitter, J.-M., Blanquet, S., and Fayat, G. (1992) J. Bacteriol. 174, 4294-4301. ..
  4. Simonetti A, Marzi S, Myasnikov A, Fabbretti A, Yusupov M, Gualerzi C, et al. Structure of the 30S translation initiation complex. Nature. 2008;455:416-20 pubmed publisher
  5. Lancaster L, Noller H. Involvement of 16S rRNA nucleotides G1338 and A1339 in discrimination of initiator tRNA. Mol Cell. 2005;20:623-32 pubmed
    ..Moreover, our findings indicate that discrimination also involves recognition of at least one additional feature of the tRNA(fMet) anticodon stem loop. ..
  6. Caserta E, Tomsic J, Spurio R, La Teana A, Pon C, Gualerzi C. Translation initiation factor IF2 interacts with the 30 S ribosomal subunit via two separate binding sites. J Mol Biol. 2006;362:787-99 pubmed
  7. Dever T, Feng L, Wek R, Cigan A, Donahue T, Hinnebusch A. Phosphorylation of initiation factor 2 alpha by protein kinase GCN2 mediates gene-specific translational control of GCN4 in yeast. Cell. 1992;68:585-96 pubmed
    ..Thus, an established mechanism for regulating total protein synthesis in mammalian cells mediates gene-specific translational control in yeast. ..
  8. Grigoriadou C, Marzi S, Kirillov S, Gualerzi C, Cooperman B. A quantitative kinetic scheme for 70 S translation initiation complex formation. J Mol Biol. 2007;373:562-72 pubmed
    ..GDPCP does not affect stable 70 S formation, but perturbs fMet-tRNA(fMet) positioning in the P-site. In contrast, thiostrepton severely retards stable 70 S formation, but allows normal binding of fMet-tRNA(fMet)(prf20) to the P-site. ..
  9. Hedegaard J, Hauge M, Fage Larsen J, Mortensen K, Kilian M, Sperling Petersen H, et al. Investigation of the translation-initiation factor IF2 gene, infB, as a tool to study the population structure of Streptococcus agalactiae. Microbiology. 2000;146 ( Pt 7):1661-70 pubmed
    ..agalactiae, yielding an evolutionary tree which had a topology similar to a tree constructed using 16S rRNA sequences from the same species. ..
  10. Zoldak G, Sedlak E, Wolfrum A, Musatov A, Fedunova D, Szkaradkiewicz K, et al. Multidomain initiation factor 2 from Thermus thermophilus consists of the individual autonomous domains. Biochemistry. 2008;47:4992-5005 pubmed publisher
    ..In conclusion, interactions between the domains of folded IF2wt in vivo are likely mediated by their alpha-helix connection and/or by a conformational change on the ribosome. ..
  11. Rasheedi S, Ghosh S, Suragani M, Tuteja N, Sopory S, Hasnain S, et al. Pisum sativum contains a factor with strong homology to eIF5B. Gene. 2007;399:144-51 pubmed
    ..Pfam domain search analysis pointed to its likely role as a translation initiation factor. The presence of an eIF5B-like factor in a plant system will aid in better understanding of the mechanism of translation initiation in plants. ..
  12. Tungkum W, Jumnongprakhon P, Tocharus C, Govitrapong P, Tocharus J. Melatonin suppresses methamphetamine-triggered endoplasmic reticulum stress in C6 cells glioma cell lines. J Toxicol Sci. 2017;42:63-71 pubmed publisher
    ..In addition, melatonin promoted the expression of Bip chaperone in a concentration-dependent manner. Taken together, our findings suggest that melatonin can protect against ER stress-induced glial cell death induced by METH. ..
  13. Campbell T, Brown E. Genetic interaction screens with ordered overexpression and deletion clone sets implicate the Escherichia coli GTPase YjeQ in late ribosome biogenesis. J Bacteriol. 2008;190:2537-45 pubmed publisher
    ..Taken in context, our work is most consistent with the hypothesis that YjeQ has a role in late 30S subunit biogenesis. ..
  14. Safiedeen Z, Rodríguez Gómez I, Vergori L, Soleti R, Vaithilingam D, Douma I, et al. Temporal Cross Talk Between Endoplasmic Reticulum and Mitochondria Regulates Oxidative Stress and Mediates Microparticle-Induced Endothelial Dysfunction. Antioxid Redox Signal. 2017;26:15-27 pubmed publisher
    ..Antioxid. Redox Signal. 26, 15-27. ..
  15. Campos F, García Gómez B, Solorzano R, Salazar E, Estevez J, Leon P, et al. A cDNA for nuclear-encoded chloroplast translational initiation factor 2 from a higher plant is able to complement an infB Escherichia coli null mutant. J Biol Chem. 2001;276:28388-94 pubmed
    ..Phylogenetic analysis using the PvIF2cp conserved region suggests that the PvIF2cp gene originated via endosymbiotic gene transfer to the nucleus and that it may be a useful marker for phylogeny reconstruction. ..
  16. Nikonorova I, Al Baghdadi R, Mirek E, Wang Y, Goudie M, Wetstein B, et al. Obesity challenges the hepatoprotective function of the integrated stress response to asparaginase exposure in mice. J Biol Chem. 2017;292:6786-6798 pubmed publisher
    ..GCN2 functions to repress mTORC1 activity and maintain ApoB100 protein levels independently of Atf4 expression, whereas hydrogen sulfide production is promoted via GCN2-ATF4 pathway. ..
  17. Hearn B, Jaishankar P, Sidrauski C, Tsai J, Vedantham P, Fontaine S, et al. Structure-Activity Studies of Bis-O-Arylglycolamides: Inhibitors of the Integrated Stress Response. ChemMedChem. 2016;11:870-80 pubmed publisher
    ..The SAR studies described herein support the proposed pharmacology of ISRIB analogues as binding across a symmetrical protein-protein interface formed between protein subunits of the dimeric eIF2B heteropentamer. ..
  18. Vornlocher H, Kreutzer R, Sprinzl M. Organization of the Thermus thermophilus nusA/infB operon and overexpression of the infB gene in Escherichia coli. Biochimie. 1997;79:195-203 pubmed
    ..The T thermophilus infB gene was expressed to a high level in E coli. Four hundred milligrams of homogenous T thermophilus IF2 were prepared from 60 g of overproducing cells...
  19. Henaut A, Lisacek F, Nitschke P, Moszer I, Danchin A. Global analysis of genomic texts: the distribution of AGCT tetranucleotides in the Escherichia coli and Bacillus subtilis genomes predicts translational frameshifting and ribosomal hopping in several genes. Electrophoresis. 1998;19:515-27 pubmed
    ..In addition, genes specific to E. coli were also studied: ompA, ompFand tolA (predicting epigenetic variation that could help escape infection by phages or colicins). ..
  20. Laalami S, Grentzmann G, Bremaud L, Cenatiempo Y. Messenger RNA translation in prokaryotes: GTPase centers associated with translational factors. Biochimie. 1996;78:577-89 pubmed
    ..Of the prokaryotic translational factors, IF2, EF-Tu, SELB, EF-G and RF3 are GTP-binding proteins. In this review we summarize the latest findings on the structures and the roles of these GTPases in the translational process. ..
  21. Nikonov O, Kravchenko O, Arkhipova V, Stolboushkina E, Nikonov S, Garber M. Water clusters in the nucleotide-binding pocket of the protein aIF2γ from the archaeon Sulfolobus solfataricus: Proton transmission. Biochimie. 2016;121:197-203 pubmed publisher
    ..We suppose that two water bridges between the oxygen atoms of the GTP γ-phosphate and negatively charged residues of the pocket can serve as ways to transmit protons arising from the catalytic reaction. ..
  22. Sullivan W, Smith A, Joyce B. Understanding mechanisms and the role of differentiation in pathogenesis of Toxoplasma gondii: a review. Mem Inst Oswaldo Cruz. 2009;104:155-61 pubmed
    ..In addition to a summary of the current state of knowledge in these areas we discuss the pharmacological ramifications and pose some questions for future research. ..
  23. Bruell C, Eichholz C, Kubarenko A, Post V, Katunin V, Hobbie S, et al. Conservation of bacterial protein synthesis machinery: initiation and elongation in Mycobacterium smegmatis. Biochemistry. 2008;47:8828-39 pubmed publisher
    ..smegmatis components as an alternative to that from E. coli to study the mechanisms of translation and to test the action of antibiotics against Gram-positive bacteria. ..
  24. Bogorad A, Lin K, Marintchev A. Novel mechanisms of eIF2B action and regulation by eIF2? phosphorylation. Nucleic Acids Res. 2017;45:11962-11979 pubmed publisher
  25. Ling C, Ermolenko D. Initiation factor 2 stabilizes the ribosome in a semirotated conformation. Proc Natl Acad Sci U S A. 2015;112:15874-9 pubmed publisher
    ..Our results suggest that positioning subunits in a semirotated orientation facilitates subunit association and support a model in which L1 stalk movement is coupled to intersubunit rotation and/or IF2 binding. ..
  26. Westergren H, Svedlund S, Momo R, Blomster J, Wåhlander K, Rehnström E, et al. Insulin resistance, endothelial function, angiogenic factors and clinical outcome in non-diabetic patients with chest pain without myocardial perfusion defects. Cardiovasc Diabetol. 2016;15:36 pubmed publisher
    ..Increased systemic pro-inflammatory state and decreased levels of pro-angiogenic vascular growth factors may be important underlying molecular mechanisms. ..
  27. Lugea A, Gerloff A, Su H, Xu Z, Go A, Hu C, et al. The Combination of Alcohol and Cigarette Smoke Induces Endoplasmic Reticulum Stress and Cell Death in Pancreatic Acinar Cells. Gastroenterology. 2017;153:1674-1686 pubmed publisher
    ..It also activates ER stress pathways that promote acinar cell death. ..
  28. Paytubi S, Morrice N, Boudeau J, Proud C. The N-terminal region of ABC50 interacts with eukaryotic initiation factor eIF2 and is a target for regulatory phosphorylation by CK2. Biochem J. 2008;409:223-31 pubmed
    ..Expression of a mutant of ABC50 in which both sites are mutated to alanine markedly decreased the association of eIF2 with 80S ribosomal and polysomal fractions...
  29. Van Melderen L, Jurenas D, Garcia Pino A. Messing up translation from the start: how AtaT inhibits translation initiation in E. coli. RNA Biol. 2017;: pubmed publisher
    ..This modification drastically impairs recognition by initiation factor 2 (IF2), thereby inhibiting the initiation step of translation...
  30. Silva R, Sattlegger E, Castilho B. Perturbations in actin dynamics reconfigure protein complexes that modulate GCN2 activity and promote an eIF2 response. J Cell Sci. 2016;129:4521-4533 pubmed
    ..These events might further contribute to GCN2 activation. Our findings indicate that GCN2 is an important sensor of the state of the actin cytoskeleton. ..
  31. Nissen P, Kjeldgaard M, Thirup S, Polekhina G, Reshetnikova L, Clark B, et al. Crystal structure of the ternary complex of Phe-tRNAPhe, EF-Tu, and a GTP analog. Science. 1995;270:1464-72 pubmed
    ..The overall shape of the ternary complex is similar to that of the translocation factor, EF-G-GDP, and this suggests a novel mechanism involving "molecular mimicry" in the translational apparatus. ..
  32. Melas P, Qvist J, Deidda M, Upreti C, Wei Y, Sanna F, et al. Cannabinoid Modulation of Eukaryotic Initiation Factors (eIF2α and eIF2B1) and Behavioral Cross-Sensitization to Cocaine in Adolescent Rats. Cell Rep. 2018;22:2909-2923 pubmed publisher
    ..These findings show that cannabinoids can modulate eukaryotic initiation factors, and they suggest a possible link between p-eIF2α and the gateway drug properties of psychoactive cannabinoids. ..
  33. Wang Y, Lei T, Yuan J, Wu Y, Shen X, Gao J, et al. GCN2 deficiency ameliorates doxorubicin-induced cardiotoxicity by decreasing cardiomyocyte apoptosis and myocardial oxidative stress. Redox Biol. 2018;17:25-34 pubmed publisher
    ..Our findings suggest that strategies to inhibit GCN2 activity in cardiomyocyte may provide a novel approach to attenuate Dox-related cardiotoxicity. ..
  34. Ramos Fernández E, Tajes M, Ill Raga G, Vargas L, Busquets Garcia A, Bosch Morató M, et al. Glutamatergic stimulation induces GluN2B translation by the nitric oxide-Heme-Regulated eIF2? kinase in cortical neurons. Oncotarget. 2016;7:58876-58892 pubmed publisher
    ..Summarizing our data suggests that glutamatergic stimulation induces HRI activation by NO to trigger GluN2B expression and this process would be relevant to maintain postsynaptic activity in cortical neurons. ..
  35. La Teana A, Pon C, Gualerzi C. Translation of mRNAs with degenerate initiation triplet AUU displays high initiation factor 2 dependence and is subject to initiation factor 3 repression. Proc Natl Acad Sci U S A. 1993;90:4161-5 pubmed
  36. Yang B, Xu Y, Hu Y, Luo Y, Lu X, Tsui C, et al. Madecassic Acid protects against hypoxia-induced oxidative stress in retinal microvascular endothelial cells via ROS-mediated endoplasmic reticulum stress. Biomed Pharmacother. 2016;84:845-852 pubmed publisher
    ..The current study indicated that the regulation of oxidative stress and ER stress by MA would be a promising therapy to reverse the process and development of hypoxia-induced hRMECs dysfunction. ..
  37. Zhang Y, Li D, Li H, Hou D, Hou J. Taurine Pretreatment Prevents Isoflurane-Induced Cognitive Impairment by Inhibiting ER Stress-Mediated Activation of Apoptosis Pathways in the Hippocampus in Aged Rats. Neurochem Res. 2016;41:2517-2525 pubmed
    ..The results indicate that taurine pretreatment prevents anesthetic isoflurane-induced cognitive impairment by inhibiting ER stress-mediated activation of apoptosis pathways in the hippocampus in aged rats. ..
  38. Jiang Z, Ma Y, Li M, Zhan X, Zhang X, Wang M. 5-Hydroxymethylfurfural protects against ER stress-induced apoptosis in GalN/TNF-α-injured L02 hepatocytes through regulating the PERK-eIF2α signaling pathway. Chin J Nat Med. 2015;13:896-905 pubmed publisher
  39. He Y, Liu C, Li X, Li R, Wang L, He K. Salubrinal attenuates right ventricular hypertrophy and dysfunction in hypoxic pulmonary hypertension of rats. Vascul Pharmacol. 2016;87:190-198 pubmed publisher
    ..These results indicate that salubrinal could prevent and reverse well-established RV remodeling, and restore the genes and pathways altered in the right ventricles of rats exposed to hypobaric hypoxia. ..
  40. Wang D, Zavadil J, Martin L, Parisi F, Friedman E, Levy D, et al. Inhibition of nonsense-mediated RNA decay by the tumor microenvironment promotes tumorigenesis. Mol Cell Biol. 2011;31:3670-80 pubmed publisher
    ..These data indicate that NMD inhibition by the tumor microenvironment is also an important mechanism to dynamically regulate genes critical for the response to cellular stress and tumorigenesis. ..
  41. Hedegaard J, Steffensen S, Nørskov Lauritsen N, Mortensen K, Sperling Petersen H. Identification of Enterobacteriaceae by partial sequencing of the gene encoding translation initiation factor 2. Int J Syst Bacteriol. 1999;49 Pt 4:1531-8 pubmed
    ..It is concluded that the inter-species variation of the infB gene fragment is sufficient for its use in the characterization of strains that have aberrant phenotypic reactions. ..
  42. Huang C, Mandava C, Sanyal S. The ribosomal stalk plays a key role in IF2-mediated association of the ribosomal subunits. J Mol Biol. 2010;399:145-53 pubmed publisher
    ..L12 depletion, however, did not affect the individual rates of the subsequent steps including GTP hydrolysis on IF2 and P(i) release. Thus, L12 is not a GTPase activating protein (GAP) for IF2 unlike as suggested for EF-G and EF-Tu. ..
  43. Wilson G, Lennox B, She P, Mirek E, Al Baghdadi R, Fusakio M, et al. GCN2 is required to increase fibroblast growth factor 21 and maintain hepatic triglyceride homeostasis during asparaginase treatment. Am J Physiol Endocrinol Metab. 2015;308:E283-93 pubmed publisher
  44. Shin B, Maag D, Roll Mecak A, Arefin M, Burley S, Lorsch J, et al. Uncoupling of initiation factor eIF5B/IF2 GTPase and translational activities by mutations that lower ribosome affinity. Cell. 2002;111:1015-25 pubmed
    ..The translational defect suggests eIF5B stabilizes Met-tRNA(i)(Met) binding and that GTP hydrolysis by eIF5B is a checkpoint monitoring 80S ribosome assembly in the final step of translation initiation. ..
  45. Nikonov O, Stolboushkina E, Nikulin A, Hasen hrl D, Bl si U, Manstein D, et al. New insights into the interactions of the translation initiation factor 2 from archaea with guanine nucleotides and initiator tRNA. J Mol Biol. 2007;373:328-36 pubmed publisher
    ..Thus, this model is in good agreement with experimental data showing that the alpha subunit of aIF2 is necessary for the stable interaction of aIF2gamma with Met-tRNA i Met...
  46. Lee J, Choi S, Roll Mecak A, Burley S, Dever T. Universal conservation in translation initiation revealed by human and archaeal homologs of bacterial translation initiation factor IF2. Proc Natl Acad Sci U S A. 1999;96:4342-7 pubmed
    ..We propose a universally conserved function for IF2 in facilitating the proper binding of initiator methionyl-tRNA to the ribosomal P site. ..
  47. Zorzet A, Pavlov M, Nilsson A, Ehrenberg M, Andersson D. Error-prone initiation factor 2 mutations reduce the fitness cost of antibiotic resistance. Mol Microbiol. 2010;75:1299-313 pubmed publisher
    ..More generally, our results suggest that bacterial protein synthesis is mRNA-limited and that compensatory mutations in IF2 could increase the persistence of PDFI-resistant bacteria in clinical settings. ..
  48. Tiennault Desbordes E, Cenatiempo Y, Laalami S. Initiation factor 2 of Myxococcus xanthus, a large version of prokaryotic translation initiation factor 2. J Bacteriol. 2001;183:207-13 pubmed
    ..The second is unique to M. xanthus IF2, is located between the APE sequence and the GTP binding domain, and consists exclusively of glycine, proline, and arginine residues. ..
  49. Asakura H, Morita Ishihara T, Yamamoto S, Igimi S. Genetic characterization of thermal tolerance in Enterobacter sakazakii. Microbiol Immunol. 2007;51:671-7 pubmed
    ..Gene expression and DNA polymorphism analyses suggested that this gene target might be useful to unequivocally detect and identify heat-resistant clones, permitting epidemiological surveillance for this pathogen. ..
  50. Novoa I, Zeng H, Harding H, Ron D. Feedback inhibition of the unfolded protein response by GADD34-mediated dephosphorylation of eIF2alpha. J Cell Biol. 2001;153:1011-22 pubmed
  51. Brady C, Cleenwerck I, Venter S, Vancanneyt M, Swings J, Coutinho T. Phylogeny and identification of Pantoea species associated with plants, humans and the natural environment based on multilocus sequence analysis (MLSA). Syst Appl Microbiol. 2008;31:447-60 pubmed publisher
    ..In conclusion, MLSA of partial nucleotide sequences of the genes gyrB, rpoB, atpD and infB can be used for classification, identification and phylogenetic analyses of Pantoea strains. ..
  52. Brandi L, Marzi S, Fabbretti A, Fleischer C, Hill W, Gualerzi C, et al. The translation initiation functions of IF2: targets for thiostrepton inhibition. J Mol Biol. 2004;335:881-94 pubmed
    ..Overall, our data indicate that the translation initiation function of IF2 is as sensitive as the translocation function of EF-G to thiostrepton inhibition. ..
  53. Milon P, Carotti M, Konevega A, Wintermeyer W, Rodnina M, Gualerzi C. The ribosome-bound initiation factor 2 recruits initiator tRNA to the 30S initiation complex. EMBO Rep. 2010;11:312-6 pubmed publisher
    ..The mechanism of action of IF2 seems to be different from that of tRNA carriers such as EF-Tu, SelB and eukaryotic initiation factor 2 (eIF2), instead resembling that of eIF5B, the eukaryotic subunit association factor. ..
  54. Qin H, Grigoriadou C, Cooperman B. Interaction of IF2 with the ribosomal GTPase-associated center during 70S initiation complex formation. Biochemistry. 2009;48:4699-706 pubmed publisher
    ..coli 70SIC, relative reactivities toward dipeptide formation of 70SICs formed with the two IF2s suggest that the Bst-IF2.GDP complex is more difficult to displace from the GAC than the E. coli IF2.GDP complex. ..
  55. Sørensen H, Sperling Petersen H, Mortensen K. A favorable solubility partner for the recombinant expression of streptavidin. Protein Expr Purif. 2003;32:252-9 pubmed
    ..coli. ..
  56. Rasmussen L, Oliveira C, Jensen J, Pedersen J, Sperling Petersen H, Mortensen K. Solution structure of C-terminal Escherichia coli translation initiation factor IF2 by small-angle X-ray scattering. Biochemistry. 2008;47:5590-8 pubmed publisher
    ..The chalice-like structure with a highly exposed alpha-helical stretch observed for the aIF5B crystal structure was not found in the structural model of IF2 in solution, in which domain VI-2 is moved closer to the rest of the protein. ..
  57. Laursen B, de A Steffensen S, Hedegaard J, Moreno J, Mortensen K, Sperling Petersen H. Structural requirements of the mRNA for intracistronic translation initiation of the enterobacterial infB gene. Genes Cells. 2002;7:901-10 pubmed
    ..Efficient intracistronic translation initiation of the infB gene is suggested to require an mRNA with this special base composition that results in an open, single-stranded structure at the ribosomal binding region. ..
  58. Krishnamoorthy T, Pavitt G, Zhang F, Dever T, Hinnebusch A. Tight binding of the phosphorylated alpha subunit of initiation factor 2 (eIF2alpha) to the regulatory subunits of guanine nucleotide exchange factor eIF2B is required for inhibition of translation initiation. Mol Cell Biol. 2001;21:5018-30 pubmed
    ..We propose that this regulatory interaction prevents association of the eIF2B catalytic subcomplex with the beta and gamma subunits of eIF2 in the manner required for GDP-GTP exchange. ..
  59. Caldas T, Laalami S, Richarme G. Chaperone properties of bacterial elongation factor EF-G and initiation factor IF2. J Biol Chem. 2000;275:855-60 pubmed
    ..These results suggest that EF-G and IF2, in addition to their role in translation, might be implicated in protein folding and protection from stress. ..
  60. Schmitt E, Guillon J, Meinnel T, Mechulam Y, Dardel F, Blanquet S. Molecular recognition governing the initiation of translation in Escherichia coli. A review. Biochimie. 1996;78:543-54 pubmed
    ..Finally, peptide deformylase and methionine aminopeptidase, which catalyze the amino terminal maturation of nascent polypeptides, can also be associated to the translation initiation process. ..
  61. Soffientini A, Lorenzetti R, Gastaldo L, Parlett J, Spurio R, La Teana A, et al. Purification procedure for bacterial translational initiation factors IF2 and IF3. Protein Expr Purif. 1994;5:118-24 pubmed
    ..Using this procedure we have been able to obtain chromatographically pure and biologically active preparations of both IF2 and IF3. ..
  62. Milon P, Tischenko E, Tomsic J, Caserta E, Folkers G, La Teana A, et al. The nucleotide-binding site of bacterial translation initiation factor 2 (IF2) as a metabolic sensor. Proc Natl Acad Sci U S A. 2006;103:13962-7 pubmed
  63. Hauryliuk V, Mitkevich V, Draycheva A, Tankov S, Shyp V, Ermakov A, et al. Thermodynamics of GTP and GDP binding to bacterial initiation factor 2 suggests two types of structural transitions. J Mol Biol. 2009;394:621-6 pubmed publisher
    ..Also, this transition is likely to protect hydrophobic groups from solvent, and its functional relevance is discussed. ..
  64. Dev K, Santangelo T, Rothenburg S, Neculai D, Dey M, Sicheri F, et al. Archaeal aIF2B interacts with eukaryotic translation initiation factors eIF2alpha and eIF2Balpha: Implications for aIF2B function and eIF2B regulation. J Mol Biol. 2009;392:701-22 pubmed publisher
    ..In this model, the evolutionarily conserved regions and sites of regulatory mutations in the three eIF2B subunits in yeast are juxtaposed in one continuous binding surface for phosphorylated eIF2alpha. ..
  65. Kapralou S, Fabbretti A, Garulli C, Spurio R, Gualerzi C, Dahlberg A, et al. Translation initiation factor IF1 of Bacillus stearothermophilus and Thermus thermophilus substitute for Escherichia coli IF1 in vivo and in vitro without a direct IF1-IF2 interaction. Mol Microbiol. 2008;70:1368-77 pubmed publisher
    ..However, the thermophilic factors do not stimulate ribosomal binding of IF2DeltaN, regardless of 30S subunits and IF2 origin. We conclude that an IF1-IF2 interaction is not universally conserved and is not essential for cell survival. ..
  66. Shazand K, Tucker J, Grunberg Manago M, Rabinowitz J, Leighton T. Similar organization of the nusA-infB operon in Bacillus subtilis and Escherichia coli. J Bacteriol. 1993;175:2880-7 pubmed
    ..subtilis infB operons suggests that the function of each gene pair is conserved and that the B. subtilis NusA homolog, which is 124 residues shorter than its E. coli counterpart, could play a role similar to its role in E. coli. ..
  67. Wilson S, Sieiro Vazquez C, Edwards N, Iourin O, Byles E, Kotsopoulou E, et al. Cloning and characterization of hIF2, a human homologue of bacterial translation initiation factor 2, and its interaction with HIV-1 matrix. Biochem J. 1999;342 ( Pt 1):97-103 pubmed
    ..hIF2 does not correspond to any of the previously characterized translation initiation factors identified in mammals, but its essential role in translation appears to have been conserved from bacteria to humans. ..
  68. Hayashi R, Ueda T, Farwell M, Takeuchi N. Nuclear respiratory factor 2 activates transcription of human mitochondrial translation initiation factor 2 gene. Mitochondrion. 2007;7:195-203 pubmed
    ..NRF-2 sites were also found in the promoters of several other mitochondrial translation factors, which suggests NRF-2 may play a key role in the regulation of mitochondrial protein synthesis. ..
  69. Delle Fratte S, Piubelli C, Domenici E. Development of a high-throughput scintillation proximity assay for the identification of C-domain translational initiation factor 2 inhibitors. J Biomol Screen. 2002;7:541-6 pubmed
    ..The assay, used to screen a limited chemical collection of about 5000 compounds and a subset of compounds originated by a 2-D substructural search, has shown to be able to detect potential IF2 inhibitors. ..
  70. Bisgaard M, Korczak B, Busse H, Kuhnert P, Bojesen A, Christensen H. Classification of the taxon 2 and taxon 3 complex of Bisgaard within Gallibacterium and description of Gallibacterium melopsittaci sp. nov., Gallibacterium trehalosifermentans sp. nov. and Gallibacterium salpingitidis sp. nov. Int J Syst Evol Microbiol. 2009;59:735-44 pubmed publisher
    ..nov. (type strain F150(T) =CCUG 15564(T) =CCUG 36325(T) =NCTC 11414(T)), a novel genomospecies 3 of Gallibacterium and an unnamed taxon (group V). An emended description of the genus Gallibacterium is also presented. ..
  71. Shazand K, Tucker J, Chiang R, Stansmore K, Sperling Petersen H, Grunberg Manago M, et al. Isolation and molecular genetic characterization of the Bacillus subtilis gene (infB) encoding protein synthesis initiation factor 2. J Bacteriol. 1990;172:2675-87 pubmed
    ..subtilis chromosome, between the polC and spcB loci. This location is distinct from those of the other major ribosomal protein and rRNA gene clusters of B. subtilis. ..
  72. Ma J, Farwell M, Burkhart W, Spremulli L. Cloning and sequence analysis of the cDNA for bovine mitochondrial translational initiation factor 2. Biochim Biophys Acta. 1995;1261:321-4 pubmed
    ..The open reading frame for bovine IF-2mt encodes a protein of 727 amino acids. The sequence of bovine IF-2mt exhibits 85% identity to human IF-2mt, but only 38% identity to yeast IF-2mt and 39% identity to Escherichia coli IF-2 alpha. ..
  73. Nørskov Lauritsen N, Sandvang D, Hedegaard J, Fussing V, Mortensen K, Sperling Petersen H, et al. Clonal origin of aminoglycoside-resistant Citrobacter freundii isolates in a Danish county. J Med Microbiol. 2001;50:636-41 pubmed
    ..The source of the strain remains unresolved. Representative isolates were obtained from various specimens from hospitals and general practice throughout the county, with no evidence of patient-to-patient transmission. ..
  74. Christensen H, Kuhnert P, Olsen J, Bisgaard M. Comparative phylogenies of the housekeeping genes atpD, infB and rpoB and the 16S rRNA gene within the Pasteurellaceae. Int J Syst Evol Microbiol. 2004;54:1601-9 pubmed publisher
    ..The phylogeny based on the housekeeping genes supported observed host associations between Mannheimia, Actinobacillus sensu stricto and [Pasteurella] trehalosi and animals with paired hooves...
  75. Christensen H, Bisgaard M, Angen O, Frederiksen W, Olsen J. Characterization of sucrose-negative Pasteurella multocida variants, including isolates from large-cat bite wounds. J Clin Microbiol. 2005;43:259-70 pubmed
    ..The evidence of phenotypic and genotypic divergence calls for the further development of PCR tests and DNA sequencing to document doubtful isolates. ..
  76. North S, Kirtland S, Nakai H. Translation factor IF2 at the interface of transposition and replication by the PriA-PriC pathway. Mol Microbiol. 2007;66:1566-78 pubmed
    ..IF2's role in the transition mechanism as well as its function as G protein and translation factor suggest its potential to regulate DNA synthesis by this pathway. ..
  77. Bohnsack J, Whiting A, Martinez G, Jones N, Adderson E, Detrick S, et al. Serotype III Streptococcus agalactiae from bovine milk and human neonatal infections. Emerg Infect Dis. 2004;10:1412-9 pubmed publisher
    ..These results support the assertion that human and bovine GBS are largely unrelated and provide further insight into the genetic relation between human and bovine GBS...
  78. Fleming K, Bohnsack J, Palacios G, Takahashi S, Adderson E. Equivalence of high-virulence clonotypes of serotype III group B Streptococcus agalactiae (GBS). J Med Microbiol. 2004;53:505-8 pubmed
    ..HVC and RDP type III-3 represent the same genetically related group of bacteria. The characteristic growth differences of virulent strains of type III GBS, however, are not directly attributable to differences in fba. ..
  79. Yatime L, Schmitt E, Blanquet S, Mechulam Y. Functional molecular mapping of archaeal translation initiation factor 2. J Biol Chem. 2004;279:15984-93 pubmed
    ..However, the N-domain of aIF2alpha interacts with RNA unspecifically. Based on this property, a possible contribution of aIF2alpha to formation of a productive complex between aIF2 and the small ribosomal subunit is envisaged. ..
  80. Laursen B, Kjaergaard A, Mortensen K, Hoffman D, Sperling Petersen H. The N-terminal domain (IF2N) of bacterial translation initiation factor IF2 is connected to the conserved C-terminal domains by a flexible linker. Protein Sci. 2004;13:230-9 pubmed
    ..The features of structurally well-ordered N- and C-terminal domains connected by a flexible linker with significant helical content are reminiscent of another translation initiation factor, IF3. ..
  81. Helgstrand M, Mandava C, Mulder F, Liljas A, Sanyal S, Akke M. The ribosomal stalk binds to translation factors IF2, EF-Tu, EF-G and RF3 via a conserved region of the L12 C-terminal domain. J Mol Biol. 2007;365:468-79 pubmed
    ..These results indicate that the L12-factor complexes will be highly populated on the ribosome, because of the high local concentration of ribosome-bound factor with respect to L12. ..
  82. Yu N, Spremulli L. Regulation of the activity of chloroplast translational initiation factor 3 by NH2- and COOH-terminal extensions. J Biol Chem. 1998;273:3871-7 pubmed
    ..The entire COOH-terminal extension reduces the proofreading ability by about half. These results are discussed in terms of the proposed three-dimensional structure of the homology domain of IF3chl. ..
  83. Steffensen S, Poulsen A, Mortensen K, Sperling Petersen H. E. coli translation initiation factor IF2--an extremely conserved protein. Comparative sequence analysis of the infB gene in clinical isolates of E. coli. FEBS Lett. 1997;419:281-4 pubmed
    ..This Gln/Gly490 is located within the central GTP/GDP-binding domain IV of IF2. The results are further evidence that IF2 from E. coli has reached a highly defined level of structural and functional development. ..
  84. Yoo J, RajBhandary U. Requirements for translation re-initiation in Escherichia coli: roles of initiator tRNA and initiation factors IF2 and IF3. Mol Microbiol. 2008;67:1012-26 pubmed publisher
    ..Strikingly, overexpression of IF3 also blocked E. coli from acting as a host for propagation of M13 phage. ..
  85. Nyengaard N, Mortensen K, Lassen S, Hershey J, Sperling Petersen H. Tandem translation of E. coli initiation factor IF2 beta: purification and characterization in vitro of two active forms. Biochem Biophys Res Commun. 1991;181:1572-9 pubmed
    ..In this assay no difference in activity is detected. ..
  86. Spencer A, Spremulli L. The interaction of mitochondrial translational initiation factor 2 with the small ribosomal subunit. Biochim Biophys Acta. 2005;1750:69-81 pubmed
    ..Mutations in this region caused a significant reduction in the ability of the factor to promote initiation complex formation and to bind 28S subunits. ..
  87. Brandi L, Fabbretti A, Milon P, Carotti M, Pon C, Gualerzi C. Methods for identifying compounds that specifically target translation. Methods Enzymol. 2007;431:229-67 pubmed
    ..Other methods presented here are suitable for secondary screening tests aimed at identifying a specific target of an antibiotic within the translational pathway of prokaryotic cells. ..
  88. Mitkevich V, Ermakov A, Kulikova A, Tankov S, Shyp V, Soosaar A, et al. Thermodynamic characterization of ppGpp binding to EF-G or IF2 and of initiator tRNA binding to free IF2 in the presence of GDP, GTP, or ppGpp. J Mol Biol. 2010;402:838-46 pubmed publisher