Monoclonal antibodies and mechanistic studies on recA protein

A protein has various epitopes, and a monoclonal antibody specifically binds to the protein by recognizing 1 of the epitopes. This characteristic of the monoclonal antibody has opened various new approaches in a wide variety of research works. In studies about recA protein and its promoted various reactions relating to genetic recombination, anti-recA protein-monoclonal antibodies are very useful to analyse reaction mechanisms and to detect transition in the higher order-structure of the protein, as well as to measure the amounts of recA protein in vitro or in vivo and to identify the related proteins. In this article, we will review studies on recA protein in which monoclonal antibodies were used as major tools. By using anti-recA protein-monoclonal IgGs as specific inhibitors, the partial reactions of the homologous pairing and strand exchange promoted by recA protein were separated, and by use of a set of anti-recA protein IgGs the stages of activation of recA protein in the above reactions were discriminated.