Hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRT) from Sulfolobus solfataricus containing GMP complexed in two different ways together with one or two MG2+
4zfn is a 2 chain structure with sequence from Sacs2. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.