Structural basis of the substrate specificity of Bacillus cereus adenosine phosphorylase.

ABSTRACT: Purine nucleoside phosphorylases catalyze the phosphorolytic cleavage of the glycosidic bond of purine (2'-deoxy)nucleosides, generating the corresponding free base and (2'-deoxy)-ribose 1-phosphate. Two classes of PNPs have been identified: homotrimers specific for 6-oxopurines and homohexamers that accept both 6-oxopurines and 6-aminopurines. Bacillus cereus adenosine phosphorylase (AdoP) is a hexameric PNP; however, it is highly specific for 6-aminopurines. To investigate the structural basis for the unique substrate specificity of AdoP, the active-site mutant D204N was prepared and kinetically characterized and the structures of the wild-type protein and the D204N mutant complexed with adenosine and sulfate or with inosine and sulfate were determined at high resolution (1.2-1.4 Å). Ado

SUBMITTER: Dessanti P 

PROVIDER: S-EPMC3282621 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature