Structural Analysis of a recA-like Gene in the Genome of Arabidopsis thaliana

A recA-like gene was identified in the genome of Arabidopsis thaliana by means of PCR using primers designed on the basis of previously reported amino acid sequences of eukaryotic RecA-like proteins. The structure of the gene, termed ArLIM15, was investigated by comparing the primary structure of the genomic DNA with that of the corresponding cDNA. The open reading frame, which was split into 15 exons, was established to have the capacity for encoding a 37.3-kDa polypeptide. The amino acid sequence of the putative product of ArLIM15 showed a high degree of similarity to that of LIM15 in the monocotyledonous plant Lilium, including a 93% identity, and to those of other recA-like genes in yeasts and vertebrates with identities of 69-71%. Phylogenetic analysis indicated ArLIM15 to be much closer to meiosis-specific LIM15 and DMC1 in Saccharomyces cerevisiae than to RAD51 in S. cerevisiae and its homologues on an evolutionary scale.