Work

Characterization of Peptidoglycan in Fem-Deletion Mutants of Methicillin-Resistant Staphylococcus aureus by Solid-State NMR

Year: 2009

Type: article

Abstract: Compositional analysis of the peptidoglycan (PG) of a wild-type methicillin-resistant Staphylococcus aureus and its fem-deletion mutants has been performed on whole cells and cell walls using stable-isotope labeling and rotational-echo double-resonance NMR. The labels included [1-(13)C,(15)N]glycine and l-[epsilon-(15)N]lysine (for a direct measure of the number of glycyl residues in the bridging segment), [1-(13)C]glycine and l-[epsilon-(15)N]lysine (concentration of bridge links), and d-[1-(13)C]alanine and [(15)N]glycine (concentrations of cross-links and wall teichoic acids). The bridging segment length changed from 5.0 glycyl residues (wild-type strain) to 2.5 +/- 0.1 (FemB) with modest changes in cross-link and bridge-link concentrations. This accurate in situ measurement for the FemB mutant indicates a heterogeneous PG structure with 25% monoglycyl and 75% triglycyl bridges. When the bridging segment was reduced to a single glycyl residue 1.0 +/- 0.1 (FemA), the level of cross-linking decreased by more than 20%, resulting in a high concentration of open N-terminal glycyl segments.

Source: Biochemistry

DOI: 10.1021/bi801750u

Authors: Shasad Sharif, Sung Joon Kim, Harald Labischinski, Jacob Schaefer

Institutions: Washington University in St. Louis, MerLion Pharma (Germany)

Language: English

Topic: Antimicrobial Resistance in Staphylococcus

Subfield: Infectious Diseases

Field: Medicine

Domain: Health Sciences

Open Access status: green

Funder: National Institute of Biomedical Imaging and Bioengineering

Awards: G6535283958, GLYCOPEPTIDE COMPLEXES WITH BACTERIAL CELL WALLS BY REDOR NMR