UvsY is a bacteriophage T4 recombinant regulatory protein, which plays a role in promoting UvsX to perform Homologous recombination. When UvsX searches for homologous sequences, it needs to compete for binding sites with Single-strand DNA-binding protein pre bound on single strand DNA, and UvsY protein promotes this competition, which is conducive to the combination of UvsX and single strand DNA. The molecular weight of UvsY protein is~16 KDa, which can enhance the DNA dependent ATPase activity of UvsX protein, reduce the minimum concentration required for its activity, and thus promote chain displacement. UvsY promotes the invasion of ssDNA single stranded binding protein complexes by UvsX recombinant enzymes, leading to the release of single stranded binding proteins and the binding of UvsX to single stranded DNA. The enzyme has no Nuclease activity.