The bimodular G57-V577 polypeptide chain of the class B penicillin-binding protein 3 of Escherichia coli catalyzes peptide bond formation from thiolesters and does not catalyze glycan chain polymerization from the lipid II intermediate.
Because the specificity profile of the membrane anchor-free G57-V577 penicillin-binding protein 3 (PBP3) of Escherichia coli for a large series of beta-lactam antibiotics is similar to that of the full-size membrane-bound PBP, the truncated PBP is expected to adopt the native folded conformation. The truncated PBP3 functions as a thiolesterase. In aqueous media and in the presence of millimolar concentrations of a properly structured amino compound, it catalyzes the aminolysis of the thiolester until completion, suggesting that the penicillin-binding module of PBP3 is designed to catalyze transpeptidation reactions. In contrast, the truncated PBP3 is devoid of glycan polymerization activity on the E. coli lipid II intermediate, suggesting that the non-penicillin-binding module of PBP3 is not a transglycosylase.
Adam
M
M
Centre d'Ingénierie des Protéines, Université de Liège, Institut de Chimie, Sart Tilman, Belgium.
Fraipont
C
C
Rhazi
N
N
Nguyen-Distèche
M
M
Lakaye
B
B
Frère
J M
JM
Devreese
B
B
Van Beeumen
J
J
van Heijenoort
Y
Y
van Heijenoort
J
J
Ghuysen
J M
JM
D000215:Acylation; D000409:Alanine / Q000031:analogs & derivatives* / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins; D002352:Carrier Proteins; D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D006031:Glycosylation; D006602:Hexosyltransferases / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D007769:Lactams; D009097:Multienzyme Complexes / Q000737:chemistry / Q000378:metabolism*; D002267:Muramoylpentapeptide Carboxypeptidase; D009842:Oligopeptides / Q000378:metabolism; D046915:Penicillin-Binding Proteins; D046928:Peptidoglycan Glycosyltransferase; D010458:Peptidyl Transferases / Q000737:chemistry / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism*; D013864:Thioglycolates / Q000378:metabolism*; D013869:Thiolester Hydrolases / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C478704:FtsI protein, E coli; D007769:Lactams; D009097:Multienzyme Complexes; D009842:Oligopeptides; D046915:Penicillin-Binding Proteins; D011134:Polysaccharides; D013864:Thioglycolates; C108445:benzoyl-alanyl-thioglycolic acid; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D046928:Peptidoglycan Glycosyltransferase; D013869:Thiolester Hydrolases; D002267:Muramoylpentapeptide Carboxypeptidase; D000409:Alanine