Conferring a template-dependent polymerase activity to terminal deoxynucleotidyltransferase by mutations in the Loop1 region.

ABSTRACT: Terminal deoxynucleotidyltransferase (Tdt) and DNA polymerase mu (pol mu) are two eukaryotic highly similar proteins involved in DNA processing and repair. Despite their high sequence identity, they differ widely in their activity: pol mu has a templated polymerase activity, whereas Tdt has a non-templated one. Loop1, first described when the Tdt structure was solved, has been invoked as the major structural determinant of this difference. Here we describe attempts to transform Tdt into pol mu with the minimal number of mutations in and around Loop1. First we describe the effect of mutations on six different positions chosen to destabilize Tdt Loop1 structure, either by alanine substitution or by deletion; they result at most in a reduction of Tdt activity, but adding Co(++) restores most

SUBMITTER: Romain F 

PROVIDER: S-EPMC2724280 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature