Specificity of L,D-transpeptidases from gram-positive bacteria producing different peptidoglycan chemotypes. - Université Paris Cité Accéder directement au contenu
Article Dans Une Revue Journal of Biological Chemistry Année : 2007

Specificity of L,D-transpeptidases from gram-positive bacteria producing different peptidoglycan chemotypes.

Résumé

We report here the first direct assessment of the specificity of a class of peptidoglycan cross-linking enzymes, the L,D-transpeptidases, for the highly diverse structure of peptidoglycan precursors of Gram-positive bacteria. The lone functionally characterized member of this new family of active site cysteine peptidases, Ldt(fm) from Enterococcus faecium, was previously shown to bypass the D,D-transpeptidase activity of the classical penicillin-binding proteins leading to high level cross-resistance to glycopeptide and beta-lactam antibiotics. Ldt(fm) homologues from Bacillus subtilis (Ldt(Bs)) and E. faecalis (Ldt(fs)) were found here to cross-link their cognate disaccharide-peptide subunits containing meso-diaminopimelic acid (mesoDAP(3)) and L-Lys(3)-L-Ala-L-Ala at the third position of the stem peptide, respectively, instead of L-Lys(3)-d-iAsn in E. faecium. Ldt(fs) differed from Ldt(fm) and Ldt(Bs) by its capacity to hydrolyze the L-Lys(3)-D-Ala(4) bond of tetrapeptide (L,D-carboxypeptidase activity) and pentapeptide (L,D-endopeptidase activity) stems, in addition to the common cross-linking activity. The three enzymes were specific for their cognate acyl acceptors in the cross-linking reaction. In contrast to Ldt(fs), which was also specific for its cognate acyl donor, Ldt(fm) tolerated substitution of L-Lys(3)-D-iAsn by L-Lys(3)-L-Ala-L-Ala. Likewise, Ldt(Bs) tolerated substitution of mesoDAP(3) by L-Lys(3)-D-iAsn and L-Lys(3)-L-Ala-L-Ala in the acyl donor. Thus, diversification of the structure of peptidoglycan precursors associated with speciation has led to a parallel evolution of the substrate specificity of the L,D-transpeptidases affecting mainly the recognition of the acyl acceptor. Blocking the assembly of the side chain could therefore be used to combat antibiotic resistance involving L,D-transpeptidases.
Fichier principal
Vignette du fichier
Magnet_et_al_M6_10911_revised.pdf (520.12 Ko) Télécharger le fichier

Dates et versions

inserm-00185684 , version 1 (06-11-2007)

Identifiants

Citer

Sophie Magnet, Ana Arbeloa, Jean-Luc Mainardi, Jean-Emmanuel Hugonnet, Martine Fourgeaud, et al.. Specificity of L,D-transpeptidases from gram-positive bacteria producing different peptidoglycan chemotypes.. Journal of Biological Chemistry, 2007, 282 (18), pp.13151-9. ⟨10.1074/jbc.M610911200⟩. ⟨inserm-00185684⟩
311 Consultations
498 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More