stx:MGAS1882_0853 K03816 xanthine phosphoribosyltransferase [EC:2.4.2.22] | (GenBank) xpt; xanthine phosphoribosyltransferase protein Xpt stx:MGAS1882_0854 K16169 xanthine permease | (GenBank) pbuX; xanthine permease protein PbuX