Altered nucleotide cofactor-dependent properties of the mutant [S240K]RecA protein.

ABSTRACT: Two mutant Escherichia coli RecA proteins were prepared in which the ATP active site residue, Ser240, was replaced with asparagine and lysine (these amino acids are found in the corresponding positions in other bacterial RecA proteins). The S240N mutation had no discernible effect on the ATP-dependent activities of the RecA protein, indicating that serine and asparagine are functionally interchangeable at position 240. The S240K mutation, in contrast, essentially eliminated the ability of the RecA protein to utilize ATP as a nucleotide cofactor. The [S240K]RecA protein was able to catalyze the hydrolysis of dATP, however, suggesting that the absence of the 2'-hydroxyl group reduced an inhibitory interaction with the Lys240 side chain. Interestingly, the [S240K]RecA protein was able to prom

SUBMITTER: Steffen SE 

PROVIDER: S-EPMC3356998 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature