title: In vitro selection of preferred DNA pairing sequences by the Escherichia coli RecA protein.
abstract: The RecA protein and other DNA strand exchange proteins are characterized by their ability to bind and pair DNA in a sequence-independent manner. In vitro selection experiments demonstrate, unexpectedly, that RecA protein has a preferential affinity for DNA sequences rich in GT composition. Such GT-rich sequences are present in loci that display increased recombinational activity in both eukaryotes and prokaryotes, including the Escherichia coli recombination hotspot, chi (5'-GCTGGTGG-3'). Interestingly, these selected sequences, or chi-containing substrates, display both an enhanced rate and extent of homologous pairing in RecA protein-dependent homologous pairing reactions. Thus, the binding and pairing of DNA by RecA protein is composition-dependent, suggesting that a component of the elevated recombinational activity of chi and increased genomic rearrangements at certain DNA sequences in eukaryotes is contributed by enhanced DNA pairing activity.
authors: Division of Biological Sciences, University of California at Davis 95616, USA.
authors: R B
authors: RB
authors: Tracy
authors: S C
authors: SC
authors: Kowalczykowski
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D018900:Dinucleotide Repeats; D008969:Molecular Sequence Data; D011938:Rec A Recombinases / Q000378:metabolism*; D013379:Substrate Specificity; D018911:Trinucleotide Repeats
chemical_list: D004247:DNA; D011938:Rec A Recombinases