Recombinase with nucleic acid exterior contact and single-chain DNA exchange activity and application of recombinase

The invention discloses a novel recombinase with nucleic acid exterior contact and single-chain DNA exchange activity, which is artificially synthesized. The recombinase comprises a nucleotide sequence shown in SEQ ID NO.1 or an amino acid sequence shown in SEQ ID NO.2. The invention discloses a composition formed by the recombinase and a kit. The invention further discloses an application of the recombinase in cloning an exogenous gene into a carrier target site. The method for cloning the exogenous gene into the carrier target site employing the novel recombinase is relatively high in accuracy rate, relatively simple and convenient, relatively fast, and relatively good in stability; and the success rate of multi-segment link is relatively high.