90 Pages

K Genetics of Cell Organelles, Structures and Function

This reaction has been extensively investigated in the bacterium Escherichia coli. In 1965, John Clark and Ann M argulies isolated the first recom bination-deficient m utants and called the gene they identified recA (Clark & M argulies, 1965). The RecA gene product has proved to be the central catalyst in the reaction. This protein form s a spiral filament around ssD N A which places the bases in a configuration

Figure 1 Homologous recombination is initiated by an exchange of DNA strands to form heteroduplex DNA adjacent to a Holliday junction. The Holliday junction is then resolved to recombinant products by cleavage and religation. Cleavage can either be at points A to generate splice products or at B to generate patch products.