title: Streptomyces K15 active-site serine DD-transpeptidase: specificity profile for peptide, thiol ester and ester carbonyl donors and pathways of the transfer reactions.
abstract: The Streptomyces K15 transferase is a penicillin-binding protein presumed to be involved in bacterial wall peptidoglycan crosslinking. It catalyses cleavage of the peptide, thiol ester or ester bond of carbonyl donors Z-R1-CONH-CHR2-COX-CHR3-COO- (where X is NH, S or O) and transfers the electrophilic group Z-R1-CONH-CHR2-CO to amino acceptors via an acyl-enzyme intermediate. Kinetic data suggest that the amino acceptor behaves as a simple alternative nucleophile at the level of the acyl-enzyme in the case of thiol ester and ester donors, and that it binds to the enzyme.carbonyl donor Michaelis complex and influences the rate of enzyme acylation by the carbonyl donor in the case of amide donors. Depending on the nature of the scissile bond, the enzyme has different requirements for substituents at positions R1, R2 and R3.
authors.affiliation: Centre d'Ingénierie des Protéines, Université de Liège, Sart Tilman, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Grandchamps
authors.forename: M
authors.initials: M
authors.lastname: Nguyen-Distèche
authors.forename: C
authors.initials: C
authors.lastname: Damblon
authors.forename: J M
authors.initials: JM
authors.lastname: Frère
authors.forename: J M
authors.initials: JM
authors.lastname: Ghuysen
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism*; D004952:Esters / Q000378:metabolism; D006602:Hexosyltransferases; D008969:Molecular Sequence Data; D002267:Muramoylpentapeptide Carboxypeptidase / Q000378:metabolism*; D046915:Penicillin-Binding Proteins; D010455:Peptides / Q000378:metabolism; D010458:Peptidyl Transferases; D013302:Streptomyces / Q000201:enzymology*; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004952:Esters; D046915:Penicillin-Binding Proteins; D010455:Peptides; D013438:Sulfhydryl Compounds; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase