Helix-hairpin-helix motifs confer salt resistance and processivity on chimeric DNA polymerases.

ABSTRACT: Helix-hairpin-helix (HhH) is a widespread motif involved in sequence-nonspecific DNA binding. The majority of HhH motifs function as DNA-binding modules with typical occurrence of one HhH motif or one or two (HhH)(2) domains in proteins. We recently identified 24 HhH motifs in DNA topoisomerase V (Topo V). Although these motifs are dispensable for the topoisomerase activity of Topo V, their removal narrows the salt concentration range for topoisomerase activity tenfold. Here, we demonstrate the utility of Topo V's HhH motifs for modulating DNA-binding properties of the Stoffel fragment of TaqDNA polymerase and Pfu DNA polymerase. Different HhH cassettes fused with either NH(2) terminus or COOH terminus of DNA polymerases broaden the salt concentration range of the polymerase activity signi

SUBMITTER: Pavlov AR 

PROVIDER: S-EPMC129704 | biostudies-literature | 2002 Oct

REPOSITORIES: biostudies-literature