Gene Symbol: aspC
Description: aspartate aminotransferase, PLP-dependent
Alias: ECK0919, JW0911
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Yano T, Kuramitsu S, Tanase S, Morino Y, Kagamiyama H. Role of Asp222 in the catalytic mechanism of Escherichia coli aspartate aminotransferase: the amino acid residue which enhances the function of the enzyme-bound coenzyme pyridoxal 5'-phosphate. Biochemistry. 1992;31:5878-87 pubmed
  2. Cho B, Cho H, Park S, Yun H, Kim B. Simultaneous synthesis of enantiomerically pure (S)-amino acids and (R)-amines using coupled transaminase reactions. Biotechnol Bioeng. 2003;81:783-9 pubmed
    ..Cloned tyrB, aspC and avtA, and omegataA were co-expressed in E. coli BL21(DE3) using pET23b(+) and pET24ma, respectively...
  3. Oue S, Okamoto A, Yano T, Kagamiyama H. Redesigning the substrate specificity of an enzyme by cumulative effects of the mutations of non-active site residues. J Biol Chem. 1999;274:2344-9 pubmed
    ..The present results demonstrate clearly the importance of the cumulative effects of residues remote from the active site and represent a new line of approach to the redesign of enzyme activity. ..
  4. Schleif R, Hirsh J. Electron microscopy of proteins bound to DNA. Methods Enzymol. 1980;65:885-96 pubmed
  5. Deu E, Kirsch J. The unfolding pathway for Apo Escherichia coli aspartate aminotransferase is dependent on the choice of denaturant. Biochemistry. 2007;46:5810-8 pubmed
    ..The free energy of unfolding of apo-eAATase (D <==> 2U) is 36 +/- 3 kcal mol-1, while that for the D* 2U transition is 24 +/- 2 kcal mol-1, both at 1 M standard state and pH 7.5. ..
  6. Furumo N, Kirsch J. Accumulation of the quinonoid intermediate in the reaction catalyzed by aspartate aminotransferase with cysteine sulfinic acid. Arch Biochem Biophys. 1995;319:49-54 pubmed
    ..No red transient species is observed under these conditions when aspartate is substituted for L-cysteine sulfinate. ..
  7. Onuffer J, Kirsch J. Redesign of the substrate specificity of Escherichia coli aspartate aminotransferase to that of Escherichia coli tyrosine aminotransferase by homology modeling and site-directed mutagenesis. Protein Sci. 1995;4:1750-7 pubmed
    ..Thus, the reactivity of eAATase with phenylalanine was increased by over three orders of magnitude without sacrificing the high transamination activity with aspartate observed for both enzymes.(ABSTRACT TRUNCATED AT 250 WORDS) ..
  8. Hayashi H, Inoue K, Nagata T, Kuramitsu S, Kagamiyama H. Escherichia coli aromatic amino acid aminotransferase: characterization and comparison with aspartate aminotransferase. Biochemistry. 1993;32:12229-39 pubmed
  9. Gloss L, Spencer D, Kirsch J. Cysteine-191 in aspartate aminotransferases appears to be conserved due to the lack of a neutral mutation pathway to the functional equivalent, alanine-191. Proteins. 1996;24:195-208 pubmed
    ..These data provide further support for the above hypothesis. ..

More Information


  1. Hayashi H, Kagamiyama H. Reaction of aspartate aminotransferase with L-erythro-3-hydroxyaspartate: involvement of Tyr70 in stabilization of the catalytic intermediates. Biochemistry. 1995;34:9413-23 pubmed
    ..This study provides a basis for subsequent spectroscopic characterization of the HOAsp-AspAT complex, which is a good model for the critical intermediate (quinonoid) structure of the AspAT-catalyzed reactions. ..
  2. Kuramitsu S, Okuno S, Ogawa T, Ogawa H, Kagamiyama H. Aspartate aminotransferase of Escherichia coli: nucleotide sequence of the aspC gene. J Biochem. 1985;97:1259-62 pubmed
    The nucleotide sequence of the aspartate aminotransferase [EC] structural gene, aspC, of Escherichia coli K-12 was determined...
  3. Planas A, Kirsch J. Reengineering the catalytic lysine of aspartate aminotransferase by chemical elaboration of a genetically introduced cysteine. Biochemistry. 1991;30:8268-76 pubmed
    ..The acidic limb of the V/KAsp versus pH profile, is lowered by 1.3 pH units, probably reflecting the similar difference in the basicity of the epsilon-NH2 group in gamma-thialysine versus that in lysine.(ABSTRACT TRUNCATED AT 250 WORDS) ..
  4. Bonner C, Fischer R, Ahmad S, Jensen R. Remnants of an ancient pathway to L-phenylalanine and L-tyrosine in enteric bacteria: evolutionary implications and biotechnological impact. Appl Environ Microbiol. 1990;56:3741-7 pubmed
    ..discrete enzyme, but rather was found to be synonymous with the combined activities of aspartate aminotransferase (aspC), aromatic aminotransferase (tyrB), and branched-chain aminotransferase (ilvE)...
  5. Toney M, Kirsch J. Tyrosine 70 fine-tunes the catalytic efficiency of aspartate aminotransferase. Biochemistry. 1991;30:7456-61 pubmed
  6. Nishimura K, Ito J, Yoshimura T, Esaki N, Soda K. A simple method for determination of stereospecificity of aminotransferases for C-4' hydrogen transfer of the coenzyme. Bioorg Med Chem. 1994;2:605-7 pubmed
    ..YM-2 and Escherichia coli, and aromatic amino acid aminotransferase of E. coli. ..
  7. Matharu A, Hayashi H, Kagamiyama H, Maras B, John R. Contributions of the substrate-binding arginine residues to maleate-induced closure of the active site of Escherichia coli aspartate aminotransferase. Eur J Biochem. 2001;268:1640-5 pubmed
    ..Proteolysis of the next most susceptible bond, at Arg25 in the double mutant, was protected by maleate demonstrating the presence of an additional site on the enzyme for binding dicarboxylates. ..
  8. Danishefsky A, Onnufer J, Petsko G, Ringe D. Activity and structure of the active-site mutants R386Y and R386F of Escherichia coli aspartate aminotransferase. Biochemistry. 1991;30:1980-5 pubmed
    ..The position of the Phe-386 side chain, however, appears to shift with respect to that of Arg-386 in the wild-type enzyme and to form new contacts with neighboring residues. ..
  9. Miyazawa K, Kawaguchi S, Okamoto A, Kato R, Ogawa T, Kuramitsu S. Construction of aminotransferase chimeras and analysis of their substrate specificity. J Biochem. 1994;115:568-77 pubmed
    ..The substrate specificity of the chimeric enzymes suggest that not only the amino acid residues in the active site but also those distant from the active site contribute to the substrate specificity of the parental aminotransferases. ..
  10. Metzler D, Metzler C, Scott R, Mollova E, Kagamiyama H, Yano T, et al. NMR studies of 1H resonances in the 10-18-ppm range for aspartate aminotransferase from Escherichia coli. J Biol Chem. 1994;269:28027-33 pubmed
    ..A large number of mutant proteins have been prepared for the E. coli enzyme. The present results provide essential information for future study of these mutants and for study of NMR spectra of isotopically labeled enzyme. ..
  11. Vacca R, Christen P, Malashkevich V, Jansonius J, Sandmeier E. Substitution of apolar residues in the active site of aspartate aminotransferase by histidine. Effects on reaction and substrate specificity. Eur J Biochem. 1995;227:481-7 pubmed
    ..The study shows that substitutions of single active-site residues may result in altered reaction and substrate specificities of pyridoxal-5'-phosphate-dependent enzymes. ..
  12. Kagamiyama H, Yagi T. Aspartate transaminase from E. coli: amino acid sequences of the NH2-terminal 33 residues and chymotryptic pyridoxyl tetrapeptide. Biochem Biophys Res Commun. 1979;89:1347-53 pubmed
  13. Kondo K, Wakabayashi S, Kagamiyama H. Structural studies on aspartate aminotransferase from Escherichia coli. Covalent structure. J Biol Chem. 1987;262:8648-57 pubmed
    ..The finding that the positions of deletions introduced into the sequence of E. coli enzyme to give the maximum homology agree well with those of the mitochondrial enzymes supports the endosymbiotic hypothesis of mitochondrial origin. ..
  14. Graber R, Kasper P, Malashkevich V, Strop P, Gehring H, Jansonius J, et al. Conversion of aspartate aminotransferase into an L-aspartate beta-decarboxylase by a triple active-site mutation. J Biol Chem. 1999;274:31203-8 pubmed
    ..e. by accelerating the specific reaction and suppressing potential side reactions. ..
  15. Cioni P, Onuffer J, Strambini G. Characterization of tryptophan phosphorescence of aspartate aminotransferase from Escherichia coli. Eur J Biochem. 1992;209:759-64 pubmed
  16. Hayashi H, Mizuguchi H, Miyahara I, Nakajima Y, Hirotsu K, Kagamiyama H. Conformational change in aspartate aminotransferase on substrate binding induces strain in the catalytic group and enhances catalysis. J Biol Chem. 2003;278:9481-8 pubmed
    ..Kinetic analysis suggested that the repulsion increases the free energy level of the Michaelis complex and promotes the catalytic reaction. ..
  17. Han Q, Fang J, Li J. Kynurenine aminotransferase and glutamine transaminase K of Escherichia coli: identity with aspartate aminotransferase. Biochem J. 2001;360:617-23 pubmed
    ..coli protein is AspAT. ..
  18. Birolo L, Sandmeier E, Christen P, John R. The roles of Tyr70 and Tyr225 in aspartate aminotransferase assessed by analysing the effects of mutations on the multiple reactions of the substrate analogue serine o-sulphate. Eur J Biochem. 1995;232:859-64 pubmed
  19. Inoue K, Kuramitsu S, Okamoto A, Hirotsu K, Higuchi T, Kagamiyama H. Site-directed mutagenesis of Escherichia coli aspartate aminotransferase: role of Tyr70 in the catalytic processes. Biochemistry. 1991;30:7796-801 pubmed
    ..mol-1, suggesting that the presence of a benzene ring at position 70 is essential for recognizing the L-glutamate-2-oxoglutarate pair as substrates. ..
  20. Goldberg J, Kirsch J. The reaction catalyzed by Escherichia coli aspartate aminotransferase has multiple partially rate-determining steps, while that catalyzed by the Y225F mutant is dominated by ketimine hydrolysis. Biochemistry. 1996;35:5280-91 pubmed
    ..C alpha H abstraction, ketimine hydrolysis, and oxalacetate dissociation are partially rate-determining. Ketimine hydrolysis is the sole rate-determining step for the corresponding Y225F- catalyzed reaction. ..
  21. Yano T, Kuramitsu S, Tanase S, Morino Y, Hiromi K, Kagamiyama H. The role of His143 in the catalytic mechanism of Escherichia coli aspartate aminotransferase. J Biol Chem. 1991;266:6079-85 pubmed
    ..All these findings suggest that, although His143 is not essential for catalysis, it might assist the formation of enzyme-substrate complex. ..
  22. Kamitori S, Okamoto A, Hirotsu K, Higuchi T, Kuramitsu S, Kagamiyama H, et al. Three-dimensional structures of aspartate aminotransferase from Escherichia coli and its mutant enzyme at 2.5 A resolution. J Biochem. 1990;108:175-84 pubmed
    ..coli and those from higher animals could be explained on the basis of the X-ray structures and molecular mechanics calculation based on them. ..
  23. Yano T, Hinoue Y, Chen V, Metzler D, Miyahara I, Hirotsu K, et al. Role of an active site residue analyzed by combination of mutagenesis and coenzyme analog. J Mol Biol. 1993;234:1218-29 pubmed
    ..These results fully support the following postulated role of Asp222: the negative charge of Asp222 stabilizes the positive charge at N(1) of PLP and thereby enhances the function of PLP as an electron sink. ..
  24. Fotheringham I, Dacey S, Taylor P, Smith T, Hunter M, Finlay M, et al. The cloning and sequence analysis of the aspC and tyrB genes from Escherichia coli K12. Comparison of the primary structures of the aspartate aminotransferase and aromatic aminotransferase of E. coli with those of the pig aspartate aminotransferase i. Biochem J. 1986;234:593-604 pubmed
    In this paper we describe the cloning and sequence analysis of the tyrB and aspC genes from Escherichia coli K12, which encode the aromatic aminotransferase and aspartate aminotransferase respectively...
  25. Deu E, Kirsch J. Cofactor-directed reversible denaturation pathways: the cofactor-stabilized Escherichia coli aspartate aminotransferase homodimer unfolds through a pathway that differs from that of the apoenzyme. Biochemistry. 2007;46:5819-29 pubmed
  26. Smith D, Ringe D, Finlayson W, Kirsch J. Preliminary X-ray data for aspartate aminotransferase from Escherichia coli. J Mol Biol. 1986;191:301-2 pubmed
    Crystals of the aspartate aminotransferase from Escherichia coli (aspC gene product) have been examined by X-ray analysis. The crystals grow as elongated rectangular prisms, with the symmetry of space group C2221...
  27. Wright S, Rishavy M, Cleland W. 2H, 13C, and 15N kinetic isotope effects on the reaction of the ammonia-rescued K258A mutant of aspartate aminotransferase. Biochemistry. 2003;42:8369-76 pubmed
  28. Almo S, Smith D, Danishefsky A, Ringe D. The structural basis for the altered substrate specificity of the R292D active site mutant of aspartate aminotransferase from E. coli. Protein Eng. 1994;7:405-12 pubmed
  29. Onuffer J, Kirsch J. Characterization of the apparent negative co-operativity induced in Escherichia coli aspartate aminotransferase by the replacement of Asp222 with alanine. Evidence for an extremely slow conformational change. Protein Eng. 1994;7:413-24 pubmed
  30. Kuramitsu S, Hiromi K, Hayashi H, Morino Y, Kagamiyama H. Pre-steady-state kinetics of Escherichia coli aspartate aminotransferase catalyzed reactions and thermodynamic aspects of its substrate specificity. Biochemistry. 1990;29:5469-76 pubmed
    ..abstract truncated at 250 words) ..
  31. Liu D, Pozharski E, Lepore B, Fu M, Silverman R, Petsko G, et al. Inactivation of Escherichia coli L-aspartate aminotransferase by (S)-4-amino-4,5-dihydro-2-thiophenecarboxylic acid reveals "a tale of two mechanisms". Biochemistry. 2007;46:10517-27 pubmed
    ..Additionally, the structural models also show pH dependence of the protein structure itself, which provided detailed mechanistic implications for l-AspAT. ..
  32. Vacca R, Giannattasio S, Graber R, Sandmeier E, Marra E, Christen P. Active-site Arg --> Lys substitutions alter reaction and substrate specificity of aspartate aminotransferase. J Biol Chem. 1997;272:21932-7 pubmed
    ..Apparently, the reaction specificity of pyridoxal 5'-phosphate-dependent enzymes is not only achieved by accelerating the specific reaction but also by preventing potential side reactions of the coenzyme substrate adduct. ..
  33. Kagamiyama H. Aspartate aminotransferase of E. coli: effects of site-directed mutagenesis on substrate recognition. J Nutr Sci Vitaminol (Tokyo). 1992;Spec No:216-9 pubmed
    ..The phenol group of Y70 is essential for the stabilization of the transition states with all substrates. Benzene ring at position 70 is necessary to recognize the glutamate-2-oxoglutarate substrate pair. ..
  34. Powell J, Morrison J. The purification and properties of the aspartate aminotransferase and aromatic-amino-acid aminotransferase from Escherichia coli. Eur J Biochem. 1978;87:391-400 pubmed
    ..Both enzymes are composed of two subunits which appear to be identical. ..
  35. Gloss L, Kirsch J. Use of site-directed mutagenesis and alternative substrates to assign the prototropic groups important to catalysis by Escherichia coli aspartate aminotransferase. Biochemistry. 1995;34:3999-4007 pubmed
    ..C alpha proton abstraction is partially rate-determining at neutral pH values, but not at pH extremes.(ABSTRACT TRUNCATED AT 250 WORDS) ..
  36. Graber R, Kasper P, Malashkevich V, Sandmeier E, Berger P, Gehring H, et al. Changing the reaction specificity of a pyridoxal-5'-phosphate-dependent enzyme. Eur J Biochem. 1995;232:686-90 pubmed
  37. Collier R, Kohlhaw G. Nonidentity of the aspartate and the aromatic aminotransferase components of transaminase A in Escherichia coli. J Bacteriol. 1972;112:365-71 pubmed
    ..The apparent molecular weights of both the aspartate and the aromatic aminotransferases, determined by gel filtration, were about 100,000. ..
  38. Mizuguchi H, Hayashi H, Okada K, Miyahara I, Hirotsu K, Kagamiyama H. Strain is more important than electrostatic interaction in controlling the pKa of the catalytic group in aspartate aminotransferase. Biochemistry. 2001;40:353-60 pubmed
    ..8 unit decrease) of the extremely low pK(a) value of the Schiff base [Hayashi, H., Mizuguchi, H., and Kagamiyama, H. (1998) Biochemistry 37, 15076-15085]. ..
  39. Rothman S, Voorhies M, Kirsch J. Directed evolution relieves product inhibition and confers in vivo function to a rationally designed tyrosine aminotransferase. Protein Sci. 2004;13:763-72 pubmed
    ..Both residues are in close proximity to Arg292 and the mutations may function to modulate the arginine switch mechanism responsible for dual substrate recognition in TATases and HEX. ..
  40. Jeffery C, Gloss L, Petsko G, Ringe D. The role of residues outside the active site: structural basis for function of C191 mutants of Escherichia coli aspartate aminotransferase. Protein Eng. 2000;13:105-12 pubmed
    ..Instead, rotation around the C(alpha)-C(beta) bond allowed each large aromatic side chain to become buried in a nearby pocket without large changes in the enzyme's backbone geometry. ..
  41. Mavrides C, Orr W. Multispecific aspartate and aromatic amino acid aminotransferases in Escherichia coli. J Biol Chem. 1975;250:4128-33 pubmed
    ..The two enzymes appear to be products of two genes different in a small, probably terminal, nucleotide sequence. ..
  42. Kondo K, Wakabayashi S, Yagi T, Kagamiyama H. The complete amino acid sequence of aspartate aminotransferase from Escherichia coli: sequence comparison with pig isoenzymes. Biochem Biophys Res Commun. 1984;122:62-7 pubmed
    ..coli enzyme exhibited the same degree of homology (about 40%) with either of them. Although majority of the residues were substituted, the functional residues constituting the active site structure were conserved. ..
  43. Matsushima Y, Kim D, Yoshimura T, Kuramitsu S, Kagamiyama H, Esaki N, et al. Replacement of active-site lysine-239 of thermostable aspartate aminotransferase by S-(2-aminoethyl)cysteine: properties of the mutant enzyme. J Biochem. 1994;115:108-12 pubmed
    ..6-24 times lower than those for the wild-type enzyme ones. The two enzymes showed similar Kd values for the same substrates except glutamate; the mutant enzyme showed higher affinity for glutamate than the wild-type enzyme. ..
  44. Birolo L, Malashkevich V, Capitani G, De Luca F, Moretta A, Jansonius J, et al. Functional and structural analysis of cis-proline mutants of Escherichia coli aspartate aminotransferase. Biochemistry. 1999;38:905-13 pubmed
  45. Toney M, Kirsch J. Kinetics and equilibria for the reactions of coenzymes with wild type and the Y70F mutant of Escherichia coli aspartate aminotransferase. Biochemistry. 1991;30:7461-6 pubmed
    ..The delta G for association of PLP with wild type enzyme is 4.7 kcal/mol more favorable than that for PMP. ..
  46. Hayashi H, Mizuguchi H, Kagamiyama H. The imine-pyridine torsion of the pyridoxal 5'-phosphate Schiff base of aspartate aminotransferase lowers its pKa in the unliganded enzyme and is crucial for the successive increase in the pKa during catalysis. Biochemistry. 1998;37:15076-85 pubmed
    ..The strain of the protonated internal aldimine is interpreted to enhance the catalytic ability of the enzyme by increasing the energy level of the free enzyme plus substrate at neutral pH relative to the transition state. ..
  47. Goldberg J, Zheng J, Deng H, Chen Y, Callender R, Kirsch J. Structure of the complex between pyridoxal 5'-phosphate and the tyrosine 225 to phenylalanine mutant of Escherichia coli aspartate aminotransferase determined by isotope-edited classical Raman difference spectroscopy. Biochemistry. 1993;32:8092-7 pubmed
    ..1670 cm-1 in the spectrum of free PLP or in that of a mutant of AATase in which Lys-258 is replaced with Ala, are red-shifted by ca. 30 cm-1 in H(2)18O.(ABSTRACT TRUNCATED AT 250 WORDS) ..
  48. Jager J, Moser M, Sauder U, Jansonius J. Crystal structures of Escherichia coli aspartate aminotransferase in two conformations. Comparison of an unliganded open and two liganded closed forms. J Mol Biol. 1994;239:285-305 pubmed
    ..They will serve as reference in the interpretation of the properties of further site-directed mutants in continued studies of structure-function relationships of this enzyme. ..
  49. Deu E, Koch K, Kirsch J. The role of the conserved Lys68*:Glu265 intersubunit salt bridge in aspartate aminotransferase kinetics: multiple forced covariant amino acid substitutions in natural variants. Protein Sci. 2002;11:1062-73 pubmed
    ..The more deeply rooted tree indicates that the Csb variant was the ancestral specie. ..
  50. Berg C, Wang M, Vartak N, Liu L. Acquisition of new metabolic capabilities: multicopy suppression by cloned transaminase genes in Escherichia coli K-12. Gene. 1988;65:195-202 pubmed
  51. Yano T, Mizuno T, Kagamiyama H. A hydrogen-bonding network modulating enzyme function: asparagine-194 and tyrosine-225 of Escherichia coli aspartate aminotransferase. Biochemistry. 1993;32:1810-5 pubmed
    ..abstract truncated at 250 words) ..
  52. Okamoto A, Higuchi T, Hirotsu K, Kuramitsu S, Kagamiyama H. X-ray crystallographic study of pyridoxal 5'-phosphate-type aspartate aminotransferases from Escherichia coli in open and closed form. J Biochem. 1994;116:95-107 pubmed
    ..coli enzyme was larger than that in mitochondrial AspAT, suggesting that the structure of the domain interface is responsible for the degree of movement of the small domain. ..
  53. Geck M, Kirsch J. A novel, definitive test for substrate channeling illustrated with the aspartate aminotransferase/malate dehydrogenase system. Biochemistry. 1999;38:8032-7 pubmed
    ..This concentration is 10 times the physiological AATase concentration, which was determined in this work. The methodology can be applied generally. ..
  54. Chow M, McElroy K, Corbett K, Berger J, Kirsch J. Narrowing substrate specificity in a directly evolved enzyme: the A293D mutant of aspartate aminotransferase. Biochemistry. 2004;43:12780-7 pubmed
    ..While HEX is always in the closed conformation, HEX + A293D is observed in both the closed and a novel open conformation, allowing for more rapid product release. ..
  55. Malashkevich V, Onuffer J, Kirsch J, Jansonius J. Alternating arginine-modulated substrate specificity in an engineered tyrosine aminotransferase. Nat Struct Biol. 1995;2:548-53 pubmed
    ..An active-site arginine residue either shifts its position to electrostatically interact with charged substrates or moves aside to allow access of aromatic ligands. ..
  56. Gelfand D, Steinberg R. Escherichia coli mutants deficient in the aspartate and aromatic amino acid aminotransferases. J Bacteriol. 1977;130:429-40 pubmed
    ..The second mutation, aspC, maps at about 20 min and inactivates a nonrespressible aspartate aminotransferase that also has activity on the ..
  57. Leistler B, Herold M, Kirschner K. Collapsed intermediates in the reconstitution of dimeric aspartate aminotransferase from Escherichia coli. Eur J Biochem. 1992;205:603-11 pubmed
    ..Both the transient intermediate I* and the equilibrium intermediate M* qualify as 'collapsed intermediate' or 'molten globule' states. ..
  58. Rothman S, Kirsch J. How does an enzyme evolved in vitro compare to naturally occurring homologs possessing the targeted function? Tyrosine aminotransferase from aspartate aminotransferase. J Mol Biol. 2003;327:593-608 pubmed
  59. Deu E, Dhoot J, Kirsch J. The partially folded homodimeric intermediate of Escherichia coli aspartate aminotransferase contains a "molten interface" structure. Biochemistry. 2009;48:433-41 pubmed publisher
    ..Nuclei of tertiary structure, which are not involved in native intersubunit contacts, likely provide a scaffold for the unstructured interface of D*. Such a scaffold would account for the cooperative unfolding of the intermediate. ..
  60. Gloss L, Kirsch J. Examining the structural and chemical flexibility of the active site base, Lys-258, of Escherichia coli aspartate aminotransferase by replacement with unnatural amino acids. Biochemistry. 1995;34:12323-32 pubmed
    ..This "tethered" Brønsted analysis shows that the earlier reported poor reactivity of carboxylates in chemical rescue is due to electrostatic exclusion from the active site. ..
  61. Gloss L, Kirsch J. Decreasing the basicity of the active site base, Lys-258, of Escherichia coli aspartate aminotransferase by replacement with gamma-thialysine. Biochemistry. 1995;34:3990-8 pubmed
    ..The E.PLP and E.PMP complexes of Quint are 0.9 and 1.1 kcal/mol, respectively, more stable than those of WT.(ABSTRACT TRUNCATED AT 250 WORDS) ..
  62. Miyahara I, Hirotsu K, Hayashi H, Kagamiyama H. X-ray crystallographic study of pyridoxamine 5'-phosphate-type aspartate aminotransferases from Escherichia coli in three forms. J Biochem. 1994;116:1001-12 pubmed
    ..The water molecules located in the active site pocket were almost completely conserved between Escherichia coli and chicken mitochondrial aspartate aminotransferase with the same type of cofactor and the same conformation. ..
  63. Jager J, Pauptit R, Sauder U, Jansonius J. Three-dimensional structure of a mutant E. coli aspartate aminotransferase with increased enzymic activity. Protein Eng. 1994;7:605-12 pubmed
    ..It is concluded that the mutation has shifted the conformational equilibrium towards the closed form, which leads to generally reduced substrate Kms. ..
  64. Schiller M, Holmes L, Boeker E. Analysis of wild-type and mutant aspartate aminotransferases using integrated rate equations. Biochim Biophys Acta. 1996;1297:17-27 pubmed
  65. Ziak M, Jager J, Malashkevich V, Gehring H, Jaussi R, Jansonius J, et al. Mutant aspartate aminotransferase (K258H) without pyridoxal-5'-phosphate-binding lysine residue. Structural and catalytic properties. Eur J Biochem. 1993;211:475-84 pubmed
    ..Transmination of the internal to the external aldimine apparently can be replaced by de novo formation of the latter, and by its hydrolysis in the reverse direction. ..
  66. Malcolm B, Kirsch J. Site-directed mutagenesis of aspartate aminotransferase from E. coli. Biochem Biophys Res Commun. 1985;132:915-21 pubmed
    The gene for aspartate aminotransferase from E. coli (aspC) was subcloned into M13 phage and sequenced using the Sanger dideoxy method with synthetic oligonucleotide primers...
  67. Islam M, Hayashi H, Kagamiyama H. Reaction of aspartate aminotransferase with C5-dicarboxylic acids: comparison with the reaction with C4-dicarboxylic acids. J Biochem. 2003;134:277-85 pubmed
    ..SH(+). It is concluded that AspAT recognizes the two types of dicarboxylates with different chain lengths by changing the gross conformation of the enzyme protein. ..
  68. Chao Y, Lai Z, Chen P, Chern J. Enhanced conversion rate of L-phenylalanine by coupling reactions of aminotransferases and phosphoenolpyruvate carboxykinase in Escherichia coli K-12. Biotechnol Prog. 1999;15:453-8 pubmed
    In Escherichia coli, aspartate aminotransferase (encoded by aspC) and aromatic amino acid aminotransferase (encoded by tyrB) share overlapping substrate specificity in the syntheses of aromatic amino acids...
  69. Gelfand D, Rudo N. Mapping of the aspartate and aromatic amino acid aminotransferase genes tyrB and aspC. J Bacteriol. 1977;130:441-4 pubmed
    ..b>aspC-, which inactivates the nonrepressible aminotransferase with high activity for aspartate, maps between and is co-..
  70. Jantama K, Zhang X, Moore J, Shanmugam K, Svoronos S, Ingram L. Eliminating side products and increasing succinate yields in engineered strains of Escherichia coli C. Biotechnol Bioeng. 2008;101:881-93 pubmed publisher
    ..Deletion of two genes involved in oxaloacetate metabolism, aspartate aminotransferase (aspC) and the NAD(+)-linked malic enzyme (sfcA) (KJ122) significantly increased succinate yield (1...