RuvA

RuvA is a DNA-binding protein found in many bacteria that plays a central role in homologous recombination and DNA repair. It recognizes and binds to Holliday junctions, the four-way DNA structures that form during recombination, and it functions together with other proteins, notably RuvB and RuvC, to process these intermediates.

RuvA binds specifically to Holliday junctions and helps stabilize the four-arm structure, enabling proper alignment of homologous DNA strands. In conjunction with RuvB, an ATP-dependent DNA motor, RuvA coordinates branch migration—the progressive relocation of the crossover point along the DNA. When migration completes, RuvC cleaves the junction to resolve the recombination intermediate.

Structural studies in Escherichia coli show that RuvA forms a tetramer that binds the junction, providing a platform for DNA and RuvB interactions. This assembly ensures the junction is held in the correct geometry for migration and resolution. The RuvA–RuvB–RuvC system thus safeguards the integrity of the genome after DNA damage and during genetic exchange.

RuvA homologs are widespread among bacteria, reflecting the essential character of the RuvABC pathway in DNA repair and recombination. Loss or impairment of RuvA function leads to increased sensitivity to DNA-damaging agents and defects in recombination efficiency, underscoring its conserved role in maintaining genomic stability.

In research, RuvA is frequently cited as a model system for studying protein–DNA recognition of Holliday junctions and as part of the broader molecular machinery of homologous recombination.