title: Human Rad51 protein displays enhanced homologous pairing of DNA sequences resembling those at genetically unstable loci.
abstract: DNA strand exchange, the central step of homologous recombination, is considered to occur approximately independently of DNA sequence content. However, certain prokaryotic and eukaryotic genomic loci display either an enhanced or reduced frequency of genetic exchange. Here we show that the Homo sapiens DNA strand exchange protein, HsRad51, shows a preference for binding to single-stranded DNA sequences primarily rich in G-residues and poor in A- and C-residues, and that these DNA sequences manifest enhanced HsRad51 protein-dependent homologous pairing. Both of these properties are common to all DNA strand exchange proteins examined thus far. These preferred DNA pairing sequences resemble those found at genetic loci in human cells that cause genomic instability and lead to genetic diseases.
authors.affiliation: Section of Microbiology, Center for Genetics and Development, Microbiology Graduate Group, University of California Davis, CA 95616-8665, USA.
authors.forename: Erica M
authors.initials: EM
authors.lastname: Seitz
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Kowalczykowski
mesh_terms: D020029:Base Pairing; D001483:Base Sequence; D004277:DNA, Single-Stranded / Q000737:chemistry*; D042822:Genomic Instability; D006147:Guanine / Q000737:chemistry; D006801:Humans; D011485:Protein Binding; D051135:Rad51 Recombinase / Q000378:metabolism*; D011995:Recombination, Genetic
chemical_list: D004277:DNA, Single-Stranded; D006147:Guanine; C495153:RAD51 protein, human; D051135:Rad51 Recombinase