{PDOC00618} {PS00770; AA_TRANSFER_CLASS_4} {BEGIN} **************************************** * Aminotransferases class-IV signature * **************************************** Aminotransferases share certain mechanistic features with other pyridoxal- phosphate dependent enzymes, such as the covalent binding of the pyridoxal- phosphate group to a lysine residue. On the basis of sequence similarity, these various enzymes can be grouped [1,2] into subfamilies. One of these, called class-IV, currently consists of the following enzymes: - Branched-chain amino-acid aminotransferase (EC 2.6.1.42) (transaminase B), a bacterial (gene ilvE) and eukaryotic enzyme which catalyzes the reversible transfer of an amino group from 4-methyl-2-oxopentanoate to glutamate, to form leucine and 2-oxoglutarate. - D-alanine aminotransferase (EC 2.6.1.21). A bacterial enzyme which catalyzes the transfer of the amino group from D-alanine (and other D-amino acids) to 2-oxoglutarate, to form pyruvate and D-aspartate. - 4-amino-4-deoxychorismate (ADC) lyase (gene pabC). A bacterial enzyme that converts ADC into 4-aminobenzoate (PABA) and pyruvate. The above enzymes are proteins of about 270 to 415 amino-acid residues that share a few regions of sequence similarity. Surprisingly, the best conserved region does not include the lysine residue to which the pyridoxal-phosphate group is known to be attached, in ilvE. The region we use as a signature pattern is located some 40 residues at the C-terminus side of the PlP-lysine. -Consensus pattern: E-x-[STAGCI]-x(2)-N-[LIVMFAC]-[FY]-x(6,12)-[LIVMFA]-x-T- x(6,8)-[LIVM]-x-[GS]-[LIVM]-x-[KR] -Sequences known to belong to this class detected by the pattern: ALL. -Other sequence(s) detected in Swiss-Prot: 1. -Last update: December 2001 / Pattern and text revised. [ 1] Green J.M., Merkel W.K., Nichols B.P. "Characterization and sequence of Escherichia coli pabC, the gene encoding aminodeoxychorismate lyase, a pyridoxal phosphate-containing enzyme." J. Bacteriol. 174:5317-5323(1992). PubMed=1644759 [ 2] Bairoch A. Unpublished observations (1992). -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}