The cytoplasmic peptidoglycan precursor of vancomycin-resistant Enterococcus faecalis terminates in lactate

Abstract

Vancomycin resistance plasmids in enterococci carry the genes vanH and vanA, which encode enzymes catalyzing, respectively, the reduction of 2-keto acids to 2-D-hydroxy acids and the addition of D-hydroxy acids to D-alanine. It has therefore been postulated that resistant cells produce peptidoglycan precursors that terminate in the depsipeptide D-alanine-2-D-hydroxy acid rather than the dipeptide D-alanine-D-alanine, thus preventing vancomycin binding (M. Arthur, C. Molinas, T.

Structure of peptidoglycan from Thermus thermophilus HB8

“…To further characterize muropeptides 8 and 18, both were analyzed by CID MS, the most powerful tool for the structural analysis of muropeptides (2,27,28,36,46,58). Low-energy CID of the single-charged positive molecular ion of muropeptide 18 (m/z 1,130.4) yielded a large number of product ions as shown in Fig.…”

Identification of a common protease‐sensitive region in d‐alanyl‐d‐alanine and d‐alanyl‐d‐lactate ligases and photoaffinity labeling with 8‐azido ATP

“…Alaz = 40 mM) (Dutka-Malen et al, 1990;Bugg et al, 1991a,b). A predicted D-Ala-D-lactate terminus, resistant to vancomycin recognition, has been detected in these glycopeptide-resistant bacteria (Handwerger et al, 1992;Messer & Reynolds, 1992). Given the similarities in primary structure and the alteration in substrate specificity among Ddl and VanA ligases, we have sought to identify regions of the enzymes that are important to function.…”

Presence of UDP-N-acetylmuramyl-hexapeptides and -heptapeptides in enterococci and staphylococci after treatment with ramoplanin, tunicamycin, or vancomycin

“…In particular, the presence of unusual nucleotide precursors such as UDPMurNAc-pentadepsipeptide and UDP-MurNAc-tetrapeptide-D-Ser involved in the resistance of various gram-positive bacteria against glycopeptide antibiotics has been investigated by this method (1,4,5,12,13,21). More recently, qualitative and quantitative analyses of complex mixtures were greatly facilitated by coupling HPLC with mass spectrometry (MS).…”

“…More recently, qualitative and quantitative analyses of complex mixtures were greatly facilitated by coupling HPLC with mass spectrometry (MS). This approach has just been used successfully to analyze both nucleotide precursors (12,13) and fragments (6, 7) of bacterial peptidoglycan. Here it was extended to the analysis of the nucleotide precursor contents of extracts from enterococci and staphylococci treated with ramoplanin, tunicamycin, or vancomycin.…”