Plays a major role in decreasing resistance to glycopeptide antibiotics. Strongly induced by teicoplanin, vancomycin and oxacillin in strain RN4220, a restriction defective laboratory strain derived from NCTC 8325. Increased in resistance against glycopeptide antibiotics, especially teicoplanin. The resistance phenotype is lowered by several folds in strains carrying mutations in the rsbU gene which codes for a positive regulator of sigma-B. Belongs to the TcaA family.