SACCHAROMYCES CEREVISIAE HYPOXANTHINE-GUANINE PHOSPHORIBOSYLTRANSFERASE IN COMPLEX WITH GMP (GUANOSINE 5' -MONOPHOSPHATE) (TETRAGONAL CRYSTAL FORM) 2JKY TRANSFERASE, NUCLEUS, CYTOPLASM, MAGNESIUM, GMP COMPLEX, FLIP PEPTIDE-PLANE, GLYCOSYLTRANSFERASE, METAL-BINDING, PURINE SALVAGE