Cloning and expression of recombinase A from Meiothermus ruber

Abstract

The recombinase A (RecA) plays a critical role in the repair and maintenance of DNA. Interaction of the RecA protein with DNA and a nucleotide triphosphate cofactor, such as ATP, is essential for its ability to catalyze homologous pairing and subsequent transfer of strands among a variety of DNA substrates in vitro. Both mesophilic and thermophilic microorganisms were found to express the RecA protein. Proteins from thermophilic bacteria are of particular interest in the recent years because of their heat-stable properties. In the current study, the RecA protein from moderately thermophilic bacteria Meiothermus ruber has been cloned, expressed in E. coli and purified. The recombinant RecA from M. ruber has been found in the soluble fraction of transformed E. coli cells. The RecA from M. ruber is the first protein of this family, identified in moderately thermophilic bacteria so far. It shows a high sequence homology with the RecA protein from T. thermophilus. The RecA from M. ruber purified to homogeneity might be useful for the optimization of PCR-based assays. Keywords: recA gene, Meiothermus ruber, recombinase, thermophilic bacteria