Protein Domain : DNA recombination/repair protein Rad51 IPR011941

Type	Family
Description	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 [ ].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 [ ]. 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 [].Rad51 contains an N-terminal α-helical DNA binding domain not found in RecA, and a RecA-like C-terminal ATPase domain [ , ]. The active form of this protein is a long helical filament where the catalytically active unit is a homodimer [].
Short Name	DNA_recomb/repair_Rad51