Identification of three additional femAB-like open reading frames in Staphylococcus aureus

Three new proteins, FmhA, FmhB and FmhC, with significant identities to Fem A and FemB were identified in the Staphylococcus aureus (ATCC 55748) genome database. They were mapped to the SmaI-C, SmaI-H and SmaI-A fragments of t he S. aureus 8325 chromosome, respectively. Whereas insertional inactivatio n of fmhA and fmhC had no effects on growth, antibiotic susceptibility, lys ostaphin resistance, or peptidoglycan composition of the strains, fmhB coul d not be inactivated, strongly suggesting that fmhB may be an essential gen e. As deduced from the functions of FemA and FemB which are involved in the synthesis of the peptidoglycan pentaglycine interpeptide, FmhB may be a ca ndidate for the postulated FemX thought to add the first glycine to the nas cent interpeptide. (C) 1999 Federation of European Microbiological Societie s. Published by Elsevier Science B.V. All rights reserved.