CHARACTERIZATION OF SIN, A POTENTIAL RECOMBINASE-ENCODING GENE FROM STAPHYLOCOCCUS-AUREUS

The staphylococcal beta-lactamase (Bla) transposon Tn4002 has previous ly been reported to have a high level of insertional specificity for a 1.8-kb region on the plasmid pSK1. Nucleotide sequences of this regio n and of a related region on plasmid pI9789 were determined. Sequence analysis revealed that these two plasmids contain sin, a gene whose de duced product shows similarity to a family of DNA recombinases. Southe rn hybridisation analysis indicated that sin is located on alpha-, bet a- and gamma-families of Bla plasmids and on pSK1 family plasmids. A r egion of dyad symmetry located upstream from sin on pSK1 and pI9789 wa s identified as the site of insertions of Tn552 and Tn4002 in separate isolates.