HOMOLOGOUS RECOMBINATION PROTEINS IN PROKARYOTES AND EUKARYOTES

Genetic recombination is common to all forms of life and involves the exchange of DNA sequences between two chromosomes or DNA molecules. Su ch exchanges contribute to the generation of genetic diversity and the repair of damaged DNA. There are two major classes of recombination, site-specific recombination and general or homologous recombination. I n homologous recombination the joining of the DNA duplexes exhibits a similar degree of precision or fidelity but, generally speaking, does not take place at specific sites. Since exchange can occur anywhere al ong the length of two homologous chromosomes, it follows that the prot eins that catalyze homologous recombination are not sequence- or site- specific binding proteins. This review focuses on genetic and biochemi cal analyses of homologous recombination proteins that carry out conju gational recombination in E, coli and meiotic recombination in eukaryo tes.