Identification of the <scp>l</scp> , <scp>d</scp> -Transpeptidases Responsible for Attachment of the Braun Lipoprotein to <i>Escherichia coli</i> Peptidoglycan

Abstract

The L,D-transpeptidase Ldt(fm) catalyzes peptidoglycan cross-linking in beta-lactam-resistant mutant strains of Enterococcus faecium. Here, we show that in Escherichia coli Ldt(fm) homologues are responsible for the attachment of the Braun lipoprotein to murein, indicating that evolutionarily related domains have been tailored to use muropeptides or proteins as acyl acceptors in the L,D-transpeptidation reaction.