title: Two purine nucleoside phosphorylases in Bacillus subtilis. Purification and some properties of the adenosine-specific phosphorylase.
abstract: Two purine nucleoside phosphorylases (purine-nucleoside:orthophosphate ribosyltransferase, EC 2.4.2.1) were purified from vegetative Bacillus subtilis cells. One enzyme, inosine-guanosine phosphorylase, showed great similarity to the homologous enzyme of Bacillus cereus. It appeared to be a tetramer of molecular weight 95 000. The other enzyme, adenosine phosphorylase, was specific for adenosine and deoxyadenosine. The molecular weight of the native enzyme was 153 000 +/- 10% and the molecular weight of the subunits was 25 500 +/- 5%. This indicates a hexameric structure. The adenosine phosphorylase was inactivated by 10(-3) M p-chloromercuribenzoate and protected against this inactivation by phosphate, adenosine and ribose 1-phosphate.
mesh_terms: D000241:Adenosine; D001412:Bacillus subtilis / Q000201:enzymology*; D006151:Guanosine; D007288:Inosine; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D010430:Pentosyltransferases / Q000302:isolation & purification*; D011683:Purine-Nucleoside Phosphorylase / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D046911:Macromolecular Substances; D006151:Guanosine; D007288:Inosine; D010430:Pentosyltransferases; D011683:Purine-Nucleoside Phosphorylase; D000241:Adenosine