CELL-WALL MONOGLYCINE CROSS-BRIDGES AND METHICILLIN HYPERSUSCEPTIBILITY IN A FEMAB NULL MUTANT OF METHICILLIN-RESISTANT STAPHYLOCOCCUS-AUREUS

Citation
Am. Stranden et al., CELL-WALL MONOGLYCINE CROSS-BRIDGES AND METHICILLIN HYPERSUSCEPTIBILITY IN A FEMAB NULL MUTANT OF METHICILLIN-RESISTANT STAPHYLOCOCCUS-AUREUS, Journal of bacteriology, 179(1), 1997, pp. 9-16
Citations number
28
Categorie Soggetti
Microbiology
Journal title
ISSN journal
00219193
Volume
179
Issue
1
Year of publication
1997
Pages
9 - 16
Database
ISI
SICI code
0021-9193(1997)179:1<9:CMCAMH>2.0.ZU;2-9
Abstract
The femAB operon is involved in the formation of the characteristic pe ntaglycine side chain of the staphylococcal peptidoglycan. Allele repl acement of the femAB operon with the tetracycline resistance determina nt tetK in a methicillin-resistant Staphylococcus aureus strain result ed in impaired growth, methicillin hypersusceptibility, and lysostaphi n resistance, The usual pentaglycine cross-bridges were replaced by mo noglycine bridges exclusively, and cross-linking of the peptidoglycan strands was drastically reduced. Complementation of the femAB null mut ant by either femA or femAB resulted in the extension of the cross-bri dges to a triglycine or a pentaglycine, respectively. This finding sug gests that FemA is responsible for the formation of glycines 2 and 3, and FemB is responsible for formation of glycines 4 and 5, of the pent aglycine side chain of the peptido-glycan precursor. Moreover, it can be deduced that addition of the first glycine must occur by a femAB-in dependent mechanism.