Conformational transitions in DNA polymerase I revealed by single-molecule FRET.

ABSTRACT: The remarkable fidelity of most DNA polymerases depends on a series of early steps in the reaction pathway which allow the selection of the correct nucleotide substrate, while excluding all incorrect ones, before the enzyme is committed to the chemical step of nucleotide incorporation. The conformational transitions that are involved in these early steps are detectable with a variety of fluorescence assays and include the fingers-closing transition that has been characterized in structural studies. Using DNA polymerase I (Klenow fragment) labeled with both donor and acceptor fluorophores, we have employed single-molecule fluorescence resonance energy transfer to study the polymerase conformational transitions that precede nucleotide addition. Our experiments clearly distinguish the open an

SUBMITTER: Santoso Y 

PROVIDER: S-EPMC2818957 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature