tgt

Summary

Gene Symbol: tgt
Description: tRNA-guanine transglycosylase
Alias: ECK0400, JW0396, vacC
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Curnow A, Garcia G. tRNA-guanine transglycosylase from Escherichia coli. Minimal tRNA structure and sequence requirements for recognition. J Biol Chem. 1995;270:17264-7 pubmed
    Previously, we have demonstrated that the tRNA-guanine transglycosylase (TGT) from Escherichia coli is capable of utilizing an in vitro generated minihelix consisting of the anticodon stem and loop sequence of E...
  2. Curnow A, Garcia G. tRNA-guanine transglycosylase from Escherichia coli: recognition of dimeric, unmodified tRNA(Tyr). Biochimie. 1994;76:1183-91 pubmed
    In order to probe the interaction between tRNA and the tRNA hypermodifying enzyme, tRNA-guanine transglycosylase (TGT) from Escherichia coli, we have undertaken the generation of E coli tRNA(Tyr) and analogues...
  3. Curnow A, Kung F, Koch K, Garcia G. tRNA-guanine transglycosylase from Escherichia coli: gross tRNA structural requirements for recognition. Biochemistry. 1993;32:5239-46 pubmed
    tRNA-guanine transglycosylase (TGT) is the enzyme responsible for the post-transcriptional modification of specific tRNAs (those for Asn, Asp, His, and Tyr) with the hypermodified base, queuine...
  4. Okada N, Nishimura S. Isolation and characterization of a guanine insertion enzyme, a specific tRNA transglycosylase, from Escherichia coli. J Biol Chem. 1979;254:3061-6 pubmed
    ..0, and the pH1 value was 4.6 to 4.8. The reaction required Mg2+ ion. 7-Methylguanine inhibited guanine insertion, but the other purine analogues tested were not inhibitory and could not replace guanine.20 ..
  5. Kittendorf J, Barcomb L, Nonekowski S, Garcia G. tRNA-guanine transglycosylase from Escherichia coli: molecular mechanism and role of aspartate 89. Biochemistry. 2001;40:14123-33 pubmed
    The enzyme tRNA-guanine transglycosylase (TGT, EC 2.4.2...
  6. Chong S, Garcia G. A versatile and general prokaryotic expression vector, pLACT7. Biotechniques. 1994;17:686, 688, 690-1 pubmed
    We have previously reported the constitutive over-expression of the tRNA-guanine transglycosylase (TGT) from plasmid pTGT1 in Escherichia coli...
  7. Chong S, Curnow A, Huston T, Garcia G. tRNA-guanine transglycosylase from Escherichia coli is a zinc metalloprotein. Site-directed mutagenesis studies to identify the zinc ligands. Biochemistry. 1995;34:3694-701 pubmed
    tRNA-guanine transglycosylase (TGT) from Escherichia coli catalyzes the exchange of the queuine precursor, preQ1, into tRNA as part of the biosynthetic pathway for the posttranscriptionally modified base, queuine...
  8. Garcia G, Chervin S, Kittendorf J. Identification of the rate-determining step of tRNA-guanine transglycosylase from Escherichia coli. Biochemistry. 2009;48:11243-51 pubmed publisher
    ..is present in tRNA because of a unique base-exchange process catalyzed by tRNA-guanine transglycosylase (TGT). Previous studies have suggested the intermediacy of a covalent TGT-RNA complex...
  9. Goodenough Lashua D, Garcia G. tRNA-guanine transglycosylase from E. coli: a ping-pong kinetic mechanism is consistent with nucleophilic catalysis. Bioorg Chem. 2003;31:331-44 pubmed
    tRNA-guanine transglycosylase (TGT) is a key enzyme in the post-transcriptional modification of certain tRNAs with the pyrrolopyrimidine base queuine...

More Information

Publications43

  1. Nonekowski S, Garcia G. tRNA recognition by tRNA-guanine transglycosylase from Escherichia coli: the role of U33 in U-G-U sequence recognition. RNA. 2001;7:1432-41 pubmed
    ..One of the key enzymes in this pathway, tRNA-guanine transglycosylase (TGT), exchanges the genetically encoded guanine at position 34 with a queuine precursor, preQ1...
  2. Noguchi S, Nishimura Y, Hirota Y, Nishimura S. Isolation and characterization of an Escherichia coli mutant lacking tRNA-guanine transglycosylase. Function and biosynthesis of queuosine in tRNA. J Biol Chem. 1982;257:6544-50 pubmed
    ..The defective gene, named tgt, was mapped at about 9 min on the E. coli chromosome, and the gene order was shown to be phoB-tgt-tsx...
  3. Todorov K, Garcia G. Role of aspartate 143 in Escherichia coli tRNA-guanine transglycosylase: alteration of heterocyclic substrate specificity. Biochemistry. 2006;45:617-25 pubmed
    tRNA-guanine transglycosylase (TGT) is a key enzyme involved in the post-transcriptional modification of certain tRNAs in their anticodon wobble positions with queuine...
  4. Kittendorf J, Sgraja T, Reuter K, Klebe G, Garcia G. An essential role for aspartate 264 in catalysis by tRNA-guanine transglycosylase from Escherichia coli. J Biol Chem. 2003;278:42369-76 pubmed
    tRNA-guanine transglycosylase (TGT) catalyzes a post-transcriptional base-exchange reaction involved in the incorporation of the modified base queuine (Q) into the wobble position of certain tRNAs...
  5. Stengl B, Reuter K, Klebe G. Mechanism and substrate specificity of tRNA-guanine transglycosylases (TGTs): tRNA-modifying enzymes from the three different kingdoms of life share a common catalytic mechanism. Chembiochem. 2005;6:1926-39 pubmed
    ..the reaction pathway, substrate specificity, and conformational adaptions of the binding pockets by comparison of TGT crystal structures in complex with RNA substrates of a eubacterial and an archaebacterial species...
  6. Gardel C, Johnson K, Jacq A, Beckwith J. The secD locus of E.coli codes for two membrane proteins required for protein export. EMBO J. 1990;9:3209-16 pubmed
    ..We suggest that these two proteins may form a complex in the membrane which acts at late steps in the export process. ..
  7. Eric Thomas C, Chen Y, Garcia G. Differential heterocyclic substrate recognition by, and pteridine inhibition of E. coli and human tRNA-guanine transglycosylases. Biochem Biophys Res Commun. 2011;410:34-9 pubmed publisher
    ..Nuc. Acids Res. 39 (2011) 2834 [15]). A series of mutants of the E. coli TGT have been constructed to probe the role of three other active site amino acids in the differential recognition of ..
  8. Brenk R, Stubbs M, Heine A, Reuter K, Klebe G. Flexible adaptations in the structure of the tRNA-modifying enzyme tRNA-guanine transglycosylase and their implications for substrate selectivity, reaction mechanism and structure-based drug design. Chembiochem. 2003;4:1066-77 pubmed
    The enzyme tRNA-guanine transglycosylase (TGT, EC 2.4.2.29) catalyses a base-exchange reaction that leads to anticodon modifications of certain tRNAs. The TGT enzymes of the eubacteria Zymomonas mobilis (Z...
  9. De Crecy Lagard V. Identification of genes encoding tRNA modification enzymes by comparative genomics. Methods Enzymol. 2007;425:153-83 pubmed
    ..Methods that link gene and function but do not rely on sequence homology will be detailed, with examples taken from the tRNA modification field. ..
  10. Reuter K, Ficner R. Sequence analysis and overexpression of the Zymomonas mobilis tgt gene encoding tRNA-guanine transglycosylase: purification and biochemical characterization of the enzyme. J Bacteriol. 1995;177:5284-8 pubmed
    tRNA-guanine transglycosylase (Tgt) is involved in the biosynthesis of the hypermodified tRNA nucleoside queuosine (Q)...
  11. Lucht J, Boos W, Bremer E. Alignment of genes from the 9-minute region (araJ to tsx) of the Escherichia coli K-12 linkage map to the physical map. J Bacteriol. 1992;174:1709-10 pubmed
  12. Chen Y, Brooks A, Goodenough Lashua D, Kittendorf J, Showalter H, Garcia G. Evolution of eukaryal tRNA-guanine transglycosylase: insight gained from the heterocyclic substrate recognition by the wild-type and mutant human and Escherichia coli tRNA-guanine transglycosylases. Nucleic Acids Res. 2011;39:2834-44 pubmed publisher
    The enzyme tRNA-guanine transglycosylase (TGT) is involved in the queuosine modification of tRNAs in eukarya and eubacteria and in the archaeosine modification of tRNAs in archaea...
  13. Hoops G, Townsend L, Garcia G. tRNA-guanine transglycosylase from Escherichia coli: structure-activity studies investigating the role of the aminomethyl substituent of the heterocyclic substrate PreQ1. Biochemistry. 1995;34:15381-7 pubmed
    ..have been synthesized in order to study the substrate specificity of the tRNA-guanine transglycosylase (TGT) from Escherichia coli...
  14. Kung F, Garcia G. tRNA-guanine transglycosylase from Escherichia coli: recognition of full-length 'queuine-cognate' tRNAs. FEBS Lett. 1998;431:427-32 pubmed
    ..in the incorporation of the modified base queuine into tRNA (position 34) is tRNA-guanine transglycosylase (TGT)...
  15. Hurt J, Olgen S, Garcia G. Site-specific modification of Shigella flexneri virF mRNA by tRNA-guanine transglycosylase in vitro. Nucleic Acids Res. 2007;35:4905-13 pubmed publisher
    ..Durand and colleagues (vacC, a virulence-associated chromosomal locus of Shigella flexneri, is homologous to tgt, a gene encoding tRNA-guanine ..
  16. Todorov K, Tan X, Nonekowski S, Garcia G, Carlson H. The role of aspartic acid 143 in E. coli tRNA-guanine transglycosylase: insights from mutagenesis studies and computational modeling. Biophys J. 2005;89:1965-77 pubmed
    tRNA guanine transglycosylase (TGT) is a tRNA-modifying enzyme which catalyzes the posttranscriptional exchange of guanine in position 34 of tRNA(Y,H,N,D) with the modified base queuine in eukaryotes or its precursor, preQ(1) base, in ..
  17. Reuter K, Slany R, Ullrich F, Kersten H. Structure and organization of Escherichia coli genes involved in biosynthesis of the deazaguanine derivative queuine, a nutrient factor for eukaryotes. J Bacteriol. 1991;173:2256-64 pubmed
    The plasmid pPR20 contains the gene tgt, which encodes tRNA guanine transglycosylase (Tgt), on a 33-kbp DNA insert from a region around 9 min on the Escherichia coli linkage map...
  18. Garcia G, Koch K, Chong S. tRNA-guanine transglycosylase from Escherichia coli. Overexpression, purification and quaternary structure. J Mol Biol. 1993;231:489-97 pubmed
    tRNA-guanine transglycosylase (TGT) is the enzyme responsible for the posttranscriptional modification of specific tRNAs (Asn, Asp, His and Tyr) with queuine. In E...
  19. Garcia G, Chong S. Cysteine 265 is in the active site of, but is not essential for catalysis by tRNA-guanine transglycosylase (TGT) from Escherichia coli. J Protein Chem. 1997;16:11-7 pubmed
    ..mutagenesis and X-ray absorption spectroscopy studies have previously shown that the tRNA-guanine transglycosylase (TGT) from Escherichia coli is a zinc metalloprotein and identified the enzymic ligands to the zinc [Chong et al...
  20. Urbonavicius J, Qian Q, Durand J, Hagervall T, Bj rk G. Improvement of reading frame maintenance is a common function for several tRNA modifications. EMBO J. 2001;20:4863-73 pubmed publisher
    ..However, since the frequency of frameshifting in several different mutants [mnmA, mnmE, tgt, truA (hisT), trmD, miaA, miaB and miaE] defective in tRNA modification was higher compared with the corresponding ..
  21. Pogliano K, Beckwith J. Genetic and molecular characterization of the Escherichia coli secD operon and its products. J Bacteriol. 1994;176:804-14 pubmed
    ..operon, and found that, in addition to secD and secF, it contains the upstream gene yajC, but not the genes queA or tgt, in contrast to previous reports...
  22. Iwata Reuyl D. Biosynthesis of the 7-deazaguanosine hypermodified nucleosides of transfer RNA. Bioorg Chem. 2003;31:24-43 pubmed
    ..emphasis on the only two enzymes that have been discovered in the pathways: tRNA-guanine transglycosylase (TGT), which catalyzes the insertion of a modified base into the polynucleotide with the concomitant elimination of the ..
  23. Urbonavicius J, Stahl G, Durand J, Ben Salem S, Qian Q, Farabaugh P, et al. Transfer RNA modifications that alter +1 frameshifting in general fail to affect -1 frameshifting. RNA. 2003;9:760-8 pubmed
    Using mutants (tgt, mnmA(asuE, trmU), mnmE(trmE), miaA, miaB, miaE, truA(hisT), truB) of either Escherichia coli or Salmonella enterica serovar Typhimurium and the trm5 mutant of Saccharomyces cerevisiae, we have analyzed the influence ..
  24. Reuter K, Chong S, Ullrich F, Kersten H, Garcia G. Serine 90 is required for enzymic activity by tRNA-guanine transglycosylase from Escherichia coli. Biochemistry. 1994;33:7041-6 pubmed
    ..tRNA lacking the hypermodified wobble nucleoside queuosine (Q) due to an inactive tRNA-guanine transglycosylase (TGT)...
  25. Jänel G, Michelsen U, Nishimura S, Kersten H. Queuosine modification in tRNA and expression of the nitrate reductase in Escherichia coli. EMBO J. 1984;3:1603-8 pubmed
    ..Isogenic pairs of Escherichia coli, containing or lacking the tRNA-transglycosylase (JE 7335, tgt+ lacZ+ and JE 7337, tgt- lacZ+; JE 7334, tgt+ lacZ- and JE 7336, tgt- lacZ-), have been employed to study the ..
  26. Nonekowski S, Kung F, Garcia G. The Escherichia coli tRNA-guanine transglycosylase can recognize and modify DNA. J Biol Chem. 2002;277:7178-82 pubmed
    tRNA-guanine transglycosylase (TGT) catalyzes the exchange of queuine (or a precursor) for guanine 34 in tRNA...
  27. Hoops G, Townsend L, Garcia G. Mechanism-based inactivation of tRNA-guanine transglycosylase from Escherichia coli by 2-amino-5-(fluoromethyl)pyrrolo[2,3-d]pyrimidin-4 (3H)-one. Biochemistry. 1995;34:15539-44 pubmed
    In Escherichia coli, tRNA-guanine transglycosylase (TGT) catalyzes the incorporation of the queuine precursor preQ1 [2-amino-5-(aminomethyl)pyrrolo[2,3-d]pyrimidin-4(3H)-one] into tRNA...
  28. Garcia G, Tierney D, Chong S, Clark K, Penner Hahn J. X-ray absorption spectroscopy of the zinc site in tRNA-guanine transglycosylase from Escherichia coli. Biochemistry. 1996;35:3133-9 pubmed
    ..This reaction is catalyzed by tRNA-guanine transglycosylase (TGT). We have previously shown that the E. coli TGT is a zinc metalloprotein [Chong et al...
  29. Dineshkumar T, Thanedar S, Subbulakshmi C, Varshney U. An unexpected absence of queuosine modification in the tRNAs of an Escherichia coli B strain. Microbiology. 2002;148:3779-87 pubmed
    ..However, the lack of queuosine in tRNAs was not a common feature of all E. coli B strains. The tgt and queA genes in B105 were shown to be functional by their ability to complement tgt and queA mutant strains...
  30. Kung F, Nonekowski S, Garcia G. tRNA-guanine transglycosylase from Escherichia coli: recognition of noncognate-cognate chimeric tRNA and discovery of a novel recognition site within the TpsiC arm of tRNA(Phe). RNA. 2000;6:233-44 pubmed
    tRNA-guanine transglycosylase (TGT) is a key enzyme involved in the posttranscriptional modification of tRNA across the three kingdoms of life...
  31. Mueller S, Slany R. Structural analysis of the interaction of the tRNA modifying enzymes Tgt and QueA with a substrate tRNA. FEBS Lett. 1995;361:259-64 pubmed
    The enzymes tRNA guanine-transglycosylase (Tgt) and S-adenosylmethionine :tRNA ribosyltransferase-isomerase (QueA) participate in the biosynthesis of the hypermodified tRNA nucleoside queuosine (Q) in Escherichia coli...
  32. Nakanishi S, Ueda T, Hori H, Yamazaki N, Okada N, Watanabe K. A UGU sequence in the anticodon loop is a minimum requirement for recognition by Escherichia coli tRNA-guanine transglycosylase. J Biol Chem. 1994;269:32221-5 pubmed
    ..Our results suggest that the enzyme recognizes the U33-G34-U35 sequence in the anti-codon loop and not the tertiary structure of tRNA itself. ..
  33. Frey B, Jänel G, Michelsen U, Kersten H. Mutations in the Escherichia coli fnr and tgt genes: control of molybdate reductase activity and the cytochrome d complex by fnr. J Bacteriol. 1989;171:1524-30 pubmed
    In eubacteria, the tRNA transglycosylase (Tgt) in specific tRNAs exchanges a guanine in the anticodon for 7-aminomethyl-7-deazaguanine, which is finally converted to queuosine...
  34. Slany R, Kersten H. The promoter of the tgt/sec operon in Escherichia coli is preceded by an upstream activation sequence that contains a high affinity FIS binding site. Nucleic Acids Res. 1992;20:4193-8 pubmed
    The tgt/sec operon in E. coli consists of five genes: queA, tgt, ORF12, secD, and secF. QueA and Tgt participate in the biosynthesis of the hypermodified t-RNA nucleoside Queuosine, whereas SecD and SecF are involved in protein secretion...