restoration of the ability to catabolise the purine nucleosides in phenotypic revertants of escherichia coli k-12 mutants defective in deod encoded purine nucleoside phosphorylase ( pnpase 1 ) is the result of regulatory pndr mutations for synthesis of a second purine nucleoside phosphorylase ( pnpase 2 ) .
C2984135
pnpase 1
C1427960
pnpase