This family of proteins is found in bacteria. Proteins in this family are approximately 160 amino acids in length. Several members are associated with vancomycin virulence in Staph. aureus in some way [1]. These proteins are all lipoproteins, carrying the characteristic prokaryotic membrane-attachment site at their N-termini.

1: Serine/threonine phosphatase Stp1 contributes to reduced susceptibility to vancomycin and virulence in Staphylococcus aureus. Cameron DR, Ward DV, Kostoulias X, Howden BP, Moellering RC Jr, Eliopoulos GM, Peleg AY; J Infect Dis. 2012;205:1677-1687. PMID:22492855