Beta-glycosyltransferase TarS is an enzyme responsible for the glycosylation of wall teichoic acid polymers of the S. aureus cell wall, a process that has been shown to be specifically responsible for methicillin resistance in MRSA. It contains a trimerization domain composed of tandem carbohydrate binding motifs.The two C-terminally localized regions composed of a series of beta-sheets participate in an extensive trimerization interface and they assume an immunoglobulin-like fold. It is suggested that both carbohydrate binding domains may be involved in polyRboP binding, however unlike pullulanase, the CBMs of TarS are involved in the formation of an extensive trimerization interface [1].

1: Structure and Mechanism of Staphylococcus aureus TarS, the Wall Teichoic Acid beta-glycosyltransferase Involved in Methicillin Resistance. Sobhanifar S, Worrall LJ, King DT, Wasney GA, Baumann L, Gale RT, Nosella M, Brown ED, Withers SG, Strynadka NC; PLoS Pathog. 2016;12:e1006067. PMID:27973583