Affiliation:
1. Institute of Medical Microbiology, University of Zürich, Switzerland.
Abstract
The femAB operon is involved in the formation of the characteristic pentaglycine side chain of the staphylococcal peptidoglycan. Allele replacement of the femAB operon with the tetracycline resistance determinant tetK in a methicillin-resistant Staphylococcus aureus strain resulted in impaired growth, methicillin hypersusceptibility, and lysostaphin resistance. The usual pentaglycine cross-bridges were replaced by monoglycine bridges exclusively, and cross-linking of the peptidoglycan strands was drastically reduced. Complementation of the femAB null mutant by either femA or femAB resulted in the extension of the cross-bridges to a triglycine or a pentaglycine, respectively. This finding suggests 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 pentaglycine side chain of the peptidoglycan precursor. Moreover, it can be deduced that addition of the first glycine must occur by a femAB-independent mechanism.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference28 articles.
1. Alborn W. E. Jr. J. Hoskins J. E. Flokowitsch and P. L. Skatrud. 1994. Cloning and characterization of femA and femB genes from Staphylococcus epidermidis and Staphylococcus haemolyticus abstr. C59. In Program and Abstracts of the 34th Interscience Conference on Antimicrobial Agents and Chemotherapy. American Society for Microbiology Washington D.C.
2. Ausubel F. M. R. Brent R. E. Kingston D. D. Moore J. G. Seidman J. A. Smith and K. Struhl (ed.). 1987. Current protocols in molecular biology. Greene Publishing Associates New York N.Y.
3. Comparison of the E-test to agar dilution, broth microdilution, and agar diffusion susceptibility testing techniques by using a special challenge set of bacteria;Baker C. N.;J. Clin. Microbiol.,1991
4. Additional DNA in methicillin-resistant Staphylococcus aureus and molecular cloning of mecspecific DNA;Beck W. D.;J. Bacteriol.,1986
5. Increase in transduction efficiency of Tn551 mediated by the methicillin resistance marker;Berger-Bächi B.;J. Bacteriol.,1983