Substrate and Stereochemical Control of Peptidoglycan Cross-Linking by Transpeptidation by Escherichia coli PBP1B

Anita C. Catherwood, Adrian J. Lloyd, Julie A. Tod, Smita Chauhan, Susan E. Slade, Grzegorz P. Walkowiak, Nicola F. Galley, Avinash S. Punekar, Katie Smart, Dean Rea, Neil D. Evans, Michael J. Chappell, David, I Roper, Christopher G. Dowson

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)
43 Downloads (Pure)


Penicillin binding proteins (PBPs) catalyzing transpeptidation reactions that stabilize the peptidoglycan component of the bacterial cell wall are the targets of β-lactams, the most clinically successful antibiotics to date. However, PBP-transpeptidation enzymology has evaded detailed analysis, because of the historical unavailability of kinetically competent assays with physiologically relevant substrates and the previously unappreciated contribution of protein cofactors to PBP activity. By re-engineering peptidoglycan synthesis, we have constructed a continuous spectrophotometric assay for transpeptidation of native or near native peptidoglycan precursors and fragments by Escherichia coli PBP1B, allowing us to (a) identify recognition elements of transpeptidase substrates, (b) reveal a novel mechanism of stereochemical editing within peptidoglycan transpeptidation, (c) assess the impact of peptidoglycan substrates on β-lactam targeting of transpeptidation, and (d) demonstrate that both substrates have to be bound before transpeptidation occurs. The results allow characterization of high molecular weight PBPs as enzymes and not merely the targets of β-lactam acylation.

Original languageEnglish
Pages (from-to)5034-5048
Number of pages15
JournalJournal of the American Chemical Society
Issue number11
Early online date12 Feb 2020
Publication statusPublished - 18 Mar 2020


Dive into the research topics of 'Substrate and Stereochemical Control of Peptidoglycan Cross-Linking by Transpeptidation by Escherichia coli PBP1B'. Together they form a unique fingerprint.

Cite this