Bacillus subtilis RecU protein cleaves Holliday junctions and anneals single-stranded DNA.
Bacillus subtilis RecU protein is involved in homologous recombination, DNA repair, and chromosome segregation. Purified RecU binds preferentially to three- and four-strand junctions when compared to single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) ( approximately 10- and approximately 40-fold lower efficiency, respectively). RecU cleaves mobile four-way junctions but fails to cleave a linear dsDNA with a putative cognate site, a finding consistent with a similar genetic defect observed for genes classified within the epsilon epistatic group (namely ruvA, recD, and recU). In the presence of Mg(2+), RecU also anneals a circular ssDNA and a homologous linear dsDNA with a ssDNA tail and a linear ssDNA and a homologous supercoiled dsDNA substrate. These results suggest that RecU, which cleaves recombination intermediates with high specificity, might also help in their assembly.
Ayora
Silvia
S
Department of Microbial Biotechnology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Carrasco
Begoña
B
Doncel-Perez
Ernesto
E
Doncel
Ernesto
E
Lurz
Rudi
R
Alonso
Juan C
JC
D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers; D004269:DNA, Bacterial / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D008854:Microscopy, Electron
D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded