Homologous Genetic Recombination in Eukaryotes

Abstract

In eukaryotes, homologous recombination is mediated by genes of the RAD52 epistasis group. Several products of the RAD52 group genes function together to catalyse the homologous DNA pairing and strand exchange reaction that establishes a stable linkage between the recombining chromosomes.

Keywords: RAD52 group proteins; recombinases; homologous DNA pairing and strand exchange; genome stability; tumour suppression

Figure 1.

Steps in homologous recombination. A DNA double‐strand break is formed and processed by an exonuclease to yield single‐strand DNA tails that bear a terminal 3′‐hydroxyl group. These single‐strand tails are bound by Rad51 and other recombination factors to form a higher order nucleoprotein complex, which has the ability to locate a DNA homologue and catalyses the invasion of the homologue to form a D‐loop structure. DNA synthesis replaces the genetic information eliminated during end‐processing of the break, and resolution of the subsequent DNA intermediates followed by ligation of the remaining DNA nicks complete the process.

Figure 2.

Steps in the formation of a DNA joint. DNA homology search (step I) is effected by reiterative binding and release of the duplex (in blue) by the nucleoprotein complex consisting of single‐strand DNA (in black) and recombination proteins (in circles). Once DNA homology is located, alignment of the recombining DNA molecules occurs (step II), followed by DNA strand invasion to form a short DNA joint (step III). The length of the DNA joint is extended by a process called branch migration (step IV).

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Further Reading

Bianco PR, Tracy RB and Kowalczykowski SC (1998) DNA strand exchange proteins: a biochemical and physical comparison. Frontiers of Bioscience 3: D570–603.

Dasika GK, Lin SC, Zhao S et al. (1999) DNA damage‐induced cell cycle checkpoints and DNA strand break repair in development and tumorigenesis. Oncogene 20: 7883–7899.

Paques F and Haber JE (1999) Multiple pathways of recombination induced by double‐strand breaks in Saccharomyces cerevisiae. Microbiology and Molecular Biology Reviews 63: 349–404.

Roca AI and Cox MM (1997) RecA protein: structure, function, and role in recombinational DNA repair. Progress in Nucleic Acid Research and Molecular Biology 56: 129–223.

Stahl FW (1994) The Holliday junction on its thirtieth anniversary. Genetics 138: 241–246.

Sung P, Van Komen S and Trujillo K (2000) Recombination factors of Saccharomyces cerevisiae. Mutation Research 451: 257–275.

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How to Cite close
Sung, Patrick(Apr 2001) Homologous Genetic Recombination in Eukaryotes. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0000582]