This entry represents a domain found peptidases Xaa-Pro dipeptidyl-peptidase and glutaryl-7-aminocephalosporanic-acid acylase, which belong to MEROPS peptidase families S15. It is also found in hydrolases from the CocE/NonD family. Cocaine esterase (CocE) hydrolyzes cocaine endowing the bacteria with the ability to utilise cocaine as a sole source of carbon and energy. YcjY-like are bacterial cell division gene and LipSM54-like_FamXVI belongs also to this larger family
Title: The Structural Basis for Catalysis and Specificity of the X-Prolyl Dipeptidyl Aminopeptidase from Lactococcus lactis Rigolet P, Mechin I, Delage M, Chich J Ref: Structure (Camb), 10:1383, 2002 : PubMed
The X-prolyl dipeptidyl aminopeptidase (X-PDAP) from Lactococcus lactis is a dimeric enzyme catalyzing the removal of Xaa-Pro dipeptides from the N terminus of peptides. The structure of the enzyme was solved at 2.2 A resolution and provides a model for the peptidase family S15. Each monomer is composed of four domains. The larger one presents an alpha/beta hydrolase fold and comprises the active site serine. The specificity pocket is mainly built by residues from a small helical domain which is, together with the N-terminal domain, essential for dimerization. A C-terminal moiety probably plays a role in the tropism of X-PDAP toward the cellular membrane. These results give new insights for further exploration of the role of the enzymes of the SC clan.
Title: Gene cloning and nucleotide sequencing and properties of a cocaine esterase from Rhodococcus sp. strain MB1 Bresler MM, Rosser SJ, Basran A, Bruce NC Ref: Applied Environmental Microbiology, 66:904, 2000 : PubMed
A strain of Rhodococcus designated MB1, which was capable of utilizing cocaine as a sole source of carbon and nitrogen for growth, was isolated from rhizosphere soil of the tropane alkaloid-producing plant Erythroxylum coca. A cocaine esterase was found to initiate degradation of cocaine, which was hydrolyzed to ecgonine methyl ester and benzoate; both of these esterolytic products were further metabolized by Rhodococcus sp. strain MB1. The structural gene encoding a cocaine esterase, designated cocE, was cloned from Rhodococcus sp. strain MB1 genomic libraries by screening recombinant strains of Rhodococcus erythropolis CW25 for growth on cocaine. The nucleotide sequence of cocE corresponded to an open reading frame of 1,724 bp that codes for a protein of 574 amino acids. The amino acid sequence of cocaine esterase has a region of similarity with the active serine consensus of X-prolyl dipeptidyl aminopeptidases, suggesting that the cocaine esterase is a serine esterase. The cocE coding sequence was subcloned into the pCFX1 expression plasmid and expressed in Escherichia coli. The recombinant cocaine esterase was purified to apparent homogeneity and was found to be monomeric, with an M(r) of approximately 65,000. The apparent K(m) of the enzyme (mean +/- standard deviation) for cocaine was measured as 1.33 +/- 0.085 mM. These findings are of potential use in the development of a linked assay for the detection of illicit cocaine.
