Gene Symbol: tyrB
Description: tyrosine aminotransferase, tyrosine-repressible, PLP-dependent
Alias: ECK4046, JW4014
Species: Escherichia coli str. K-12 substr. MG1655
- 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 pubmedIn 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...
- 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. ..
- 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. ..
- Kohler E, Seville M, Jager J, Fotheringham I, Hunter M, Edwards M, et al. Significant improvement to the catalytic properties of aspartate aminotransferase: role of hydrophobic and charged residues in the substrate binding pocket. Biochemistry. 1994;33:90-7 pubmed..The generally improved catalytic efficiency of the mutant eAAT V39L appears to be due to an indirect effect, namely, the facilitated closure of the active site upon substrate binding. ..
- Cho B, Park H, Seo J, Kinnera K, Lee B, Kim B. Enzymatic resolution for the preparation of enantiomerically enriched D-beta-heterocyclic alanine derivatives using Escherichia coli aromatic L-amino acid transaminase. Biotechnol Bioeng. 2004;88:512-9 pubmed
- Gelfand D, Steinberg R. Escherichia coli mutants deficient in the aspartate and aromatic amino acid aminotransferases. J Bacteriol. 1977;130:429-40 pubmed..One mutation, designated tyrB, lies at about 80 min on the E...
- 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. ..
- 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) ..
- Kuramitsu S, Inoue K, Ogawa T, Ogawa H, Kagamiyama H. Aromatic amino acid aminotransferase of Escherichia coli: nucleotide sequence of the tyrB gene. Biochem Biophys Res Commun. 1985;133:134-9 pubmedThe tyrB gene of E. coli K-12, which encodes aromatic amino acid aminotransferase (EC 18.104.22.168) was cloned. The nucleotide sequence of about 2 kilobase pairs containing the gene was determined...
- 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. ..
- Jager J, Solmajer T, Jansonius J. Computational approach towards the three-dimensional structure of E. coli tyrosine aminotransferase. FEBS Lett. 1992;306:234-8 pubmed..coli aspartate aminotransferase and computer simulation studies. Active site characteristics of the model are correlated with experimental observations on the specificity of these enzymes towards aromatic/dicarboxylic acid substrates. ..
- 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. ..
- 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. ..
- Islam M, Hayashi H, Mizuguchi H, Kagamiyama H. The substrate activation process in the catalytic reaction of Escherichia coli aromatic amino acid aminotransferase. Biochemistry. 2000;39:15418-28 pubmed
- Hayashi H, Inoue K, Mizuguchi H, Kagamiyama H. Analysis of the substrate-recognition mode of aromatic amino acid aminotransferase by combined use of quasisubstrates and site-directed mutagenesis: systematic hydroxy-group addition/deletion studies to probe the enzyme-substrate interactions. Biochemistry. 1996;35:6754-61 pubmed..This shows that the side chain of Arg292 is partially involved in the binding of the aromatic ring of substrates to ArAT. ..
- Vartak N, Liu L, Wang B, Berg C. A functional leuABCD operon is required for leucine synthesis by the tyrosine-repressible transaminase in Escherichia coli K-12. J Bacteriol. 1991;173:3864-71 pubmedIn Escherichia coli K-12, two enzymes, encoded by ilvE and tyrB, catalyze the amination of 2-ketoisocaproate (2-KIC) to form leucine...
- 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..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...
- Onuffer J, Ton B, Klement I, Kirsch J. The use of natural and unnatural amino acid substrates to define the substrate specificity differences of Escherichia coli aspartate and tyrosine aminotransferases. Protein Sci. 1995;4:1743-9 pubmed..The present kinetic data support a model in which eAATase contains one binding mode for all classes of substrate, whereas the active site of eTATase allows an additional mode that has increased affinity for hydrophobic amino acid. ..
- 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>tyrB-, which inactivates the tyrosine-repressible component of these activities is co-transducible with metA and malB; ..
- Iwasaki M, Hayashi H, Kagamiyama H. Protonation state of the active-site Schiff base of aromatic amino acid aminotransferase: modulation by binding of ligands and implications for its role in catalysis. J Biochem. 1994;115:156-61 pubmed..Thus the structure of ArAT is deliberately organized so that the Schiff base pKa is effectively modulated by substrates having only one carboxylate group. ..
- 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
- Wu S, Hwang T, Ko T, Wang A, Tsai H. The structural interpretations of residue Ser297 in catalytic efficiency of Escherichia coli phenylalanine aminotransferase. Biochim Biophys Acta. 2003;1647:390-4 pubmed..Computational modeling of ecPheAT mutants further suggested that Ser in position 297 could make ecPheAT easy with change of conformation from open form to closed form. ..