Structure-based functional identification of Helicobacter pylori HP0268 as a nuclease with both DNA nicking and RNase activities.

ABSTRACT: HP0268 is a conserved, uncharacterized protein from Helicobacter pylori. Here, we determined the solution structure of HP0268 using three-dimensional nuclear magnetic resonance (NMR) spectroscopy, revealing that this protein is structurally most similar to a small MutS-related (SMR) domain that exhibits nicking endonuclease activity. We also demonstrated for the first time that HP0268 is a nicking endonuclease and a purine-specific ribonuclease through gel electrophoresis and fluorescence spectroscopy. The nuclease activities for DNA and RNA were maximally increased by Mn(2+) and Mg(2+) ions, respectively, and decreased by Cu(2+) ions. Using NMR chemical shift perturbations, the metal and nucleotide binding sites of HP0268 were determined to be spatially divided but close to each other. Th

SUBMITTER: Lee KY 

PROVIDER: S-EPMC4446426 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature