Nucleotide sequence of the Staphylococcus aureus gyrB-gyrA locus encoding the DNA gyrase A and B proteins

The nucleotide sequence of the gyrB-gyrA locus encoding DNA gyrase proteins in Staphylococcus aureus was analyzed and was found to consist of 5,300 base pairs. The gyrB gene codes for a 640-residue protein while gyrA encodes a 889-residue protein. Both proteins are subunits of DNA gyrase. Further studies indicate that S. aureus DNA gyrase are very similar to that of other bacteria, however, the DNA gyrase of S. aureus is more resistant to inhibition by quinolone. This contrasts the observed conservation of the amino acid sequence of bacterial gyrase proteins.