Identification of three critical acidic residues of poly(ADP-ribose) glycohydrolase involved in catalysis: determining the PARG catalytic domain.

ABSTRACT: PARG [poly(ADP-ribose) glycohydrolase] catalyses the hydrolysis of alpha(1''-->2') or alpha(1'''-->2'') O-glycosidic linkages of ADP-ribose polymers to produce free ADP-ribose. We investigated possible mechanistic similarities between PARG and glycosidases, which also cleave O-glycosidic linkages. Glycosidases typically utilize two acidic residues for catalysis, thus we targeted acidic residues within a conserved region of bovine PARG that has been shown to contain an inhibitor-binding site. The targeted glutamate and aspartate residues were changed to asparagine in order to minimize structural alterations. Mutants were purified and assayed for catalytic activity, as well as binding, to an immobilized PARG inhibitor to determine ability to recognize substrate. Our investigation revealed re

SUBMITTER: Patel CN 

PROVIDER: S-EPMC1138956 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature