Reactions of Cre with methylphosphonate DNA: similarities and contrasts with Flp and vaccinia topoisomerase.

ABSTRACT:

Background

Reactions of vaccinia topoisomerase and the tyrosine site-specific recombinase Flp with methylphosphonate (MeP) substituted DNA substrates, have provided important insights into the electrostatic features of the strand cleavage and strand joining steps catalyzed by them. A conserved arginine residue in the catalytic pentad, Arg-223 in topoisomerase and Arg-308 in Flp, is not essential for stabilizing the MeP transition state. Topoisomerase or its R223A variant promotes cleavage of the MeP bond by the active site nucleophile Tyr-274, followed by the rapid hydrolysis of the MeP-tyrosyl intermediate. Flp(R308A), but not wild type Flp, mediates direct hydrolysis of the activated MeP bond. These findings are consistent with a potential role for phosphate electrostatics and ac

SUBMITTER: Ma CH 

PROVIDER: S-EPMC2747268 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature