DNA recombination/repair protein Rad51 (IPR011941)

Short name: DNA_recomb/repair_Rad51

Overlapping homologous superfamilies

Family relationships


Homologous recombination is an evolutionarily conserved mechanism for the repair of double-strand breaks in DNA and the generation of genetic diversity. The primary function of homologous recombination in mitotic cells is to repair double-strand breaks or single-strand gaps that form as a result of replication fork collapse, from processing of spontaneous damage, and from exposure to DNA-damaging agents. During meiosis, homologous recombination is essential to establish a physical connection between homologous chromosomes to ensure their correct disjunction at the first meiotic division. In addition, the high frequency of meiotic recombination contributes to diversity by creating new linkage arrangements between genes, or parts of genes [PMID: 15568977].

The central step of homologous recombination is synapsis, the process of bringing together the two homologous strands. Rad51, a eukaryotic homologue of the prokaryotic recombinase RecA, mediates this process in eukaryotes [PMID: 1581961]. Firstly a single-stranded DNA tail is coated by ATP-bound Rad51 to yield a nucleoprotein filament. This filament then searches for a homologous sequence within double-stranded DNA, and catalyses the exchange of strands between the single-stranded and double-stranded DNA substrates. The original broken end of the resulting branched DNA is now aligned with an appropriate matching sequence in an intact duplex, and is further processed by other enzymes [PMID: 12778123].

Rad51 contains an N-terminal alpha-helical DNA binding domain not found in RecA, and a RecA-like C-terminal ATPase domain [PMID: 10390347, PMID: 12442171]. The active form of this protein is a long helical filament where the catalytically active unit is a homodimer [PMID: 15235592].

GO terms

Biological Process

GO:0000724 double-strand break repair via homologous recombination
GO:1990426 mitotic recombination-dependent replication fork processing

Molecular Function

GO:0008094 DNA-dependent ATPase activity
GO:0003690 double-stranded DNA binding
GO:0000150 recombinase activity
GO:0003697 single-stranded DNA binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.