Staphylococcus aureus sortase, an enzyme that anchors surface proteins to the cell wall

Surface proteins of Gram-positive bacteria are linked to the bacterial cell wall by a mechanism that involves cleavage of a conserved Leu-Pro-X-Thr-Gl y (LPXTG) motif and that occurs during assembly of the peptidoglycan cell w all. A Staphylococcus aureus mutant defective in the anchoring of surface p roteins was isolated and shown to carry a mutation in the srtA gene. Overex pression of srtA increased the rate of surface protein anchoring, and homol ogs of srtA were found in other pathogenic Gram-positive bacteria. The prot ein specified by srtA, sortase, may be a useful target for the development of new antimicrobial drugs.