Nucleotide sequence of the Staphylococcus aureus signal peptidase II (lsp) gene

The lsp gene encoding prolipoprotein signal peptidase (signal peptidase II) of Staphylococcus aureus was cloned by screening a genomic library for plasmid clones capable of complementing a conditionally lethal lsp allele of Escherichia coli. E. coli cells carrying one of five overlapping clones exhibited increased resistance to globomycin. The nucleotide sequence of the S. aureus lsp gene was determined. The deduced amino acid sequence of the signal peptidase II of S. aureus suggests that this enzyme has a hydropathy profile very similar to those of E. coli, Enterobacter aerogenes and Pseudomonas fluorescens. Comparison of the primary structures of this enzyme from these four distinct bacterial species reveals three highly conserved domains in proteins which have a low degree of overall sequence homology. Unlike the lsp genes from the Gram-negative bacteria, the lsp gene in S. aureus is not flanked by x-ileS and orf149-orf316 as found in E. coli, Ent. aerogenes, and P. fluorescens.