Fluorescence resonance energy transfer studies of DNA polymerase β: the critical role of fingers domain movements and a novel non-covalent step during nucleotide selection.

ABSTRACT: During DNA repair, DNA polymerase β (Pol β) is a highly dynamic enzyme that is able to select the correct nucleotide opposite a templating base from a pool of four different deoxynucleoside triphosphates (dNTPs). To gain insight into nucleotide selection, we use a fluorescence resonance energy transfer (FRET)-based system to monitor movement of the Pol β fingers domain during catalysis in the presence of either correct or incorrect dNTPs. By labeling the fingers domain with ((((2-iodoacetyl)amino)ethyl)amino)naphthalene-1-sulfonic acid (IAEDANS) and the DNA substrate with Dabcyl, we are able to observe rapid fingers closing in the presence of correct dNTPs as the IAEDANS comes into contact with a Dabcyl-labeled, one-base gapped DNA. Our findings show that not only do the fingers close afte

SUBMITTER: Towle-Weicksel JB 

PROVIDER: S-EPMC4047420 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature