Sequence of a staphylococcal plasmid gene, vga, encoding a putative ATP-binding protein involved in resistance to virginiamycin A-like antibiotics

Abstract

The Staphylococcus aureus plasmid gene, vga, conferring resistance to A compounds of virginiamycin-like antibiotics (streptogramin A, pristinamycin II, virginiamycin M), and to synergistic mixtures of the A and B compounds of these antibiotics, was cloned and sequenced. This gene potentially encodes a 522-amino acid protein, VgA, of 60,115 Da which exhibits significant homology with the ATP-binding domains of numerous proteins. VgA has two ATP-binding domains, containing each the A and the B motifs, but does not contain long hydrophobic stretches that might represent potential membrane-spanning domains. Resistance to A compounds of virginiamycin-like antibiotics conferred to S. aureus by gene vga was not conferred to Escherichia coli, although a protein having an M(r) similar to that encoded by this gene was detected in E. coli minicells.