this evidence , together with data on purification and heat-inactivation patterns of phosphoribosyltransferase activities towards the various purines , strongly suggests that there are two phosphoribosyltransferase enzymes for purine bases in schiz . pombe , one active with adenine , the other with hypoxanthine , xanthine and guanine .
C0034140
purines
C0001407
adenine