recN

recN is a bacterial gene that encodes the DNA repair protein RecN. It is found in a broad range of bacteria and some archaea and is associated with the cellular response to DNA double-strand breaks and the initiation of homologous recombination. The gene name recN is typically used for the genetic locus, while the protein is referred to as RecN.

RecN participates in early steps of double-strand break repair. It is recruited to damaged DNA and promotes processes that help stabilize and align broken ends for RecA-dependent repair. RecN often acts in concert with other RecF pathway proteins such as RecO and RecR, although the exact dependencies can vary among organisms. In several species, RecN forms nucleoprotein complexes at damage sites and uses ATP hydrolysis to remodel DNA ends, facilitating subsequent repair steps.

RecN homologs are widespread in bacteria and archaea. In Deinococcus radiodurans, for example, RecN contributes to survival after high levels of ionizing radiation and to genome reassembly following extensive fragmentation. In many Bacillus species, RecN participates in recombinational repair but is not always essential. The gene is sometimes located near recF, recO, and recR in operons, but gene organization varies across taxa, reflecting diverse regulatory and functional contexts.

Research on recN contributes to understanding the broader bacterial DNA damage response. RecN serves as a model for non-RecA-mediated steps in recombination and sheds light on the evolution of DNA repair pathways. Experimental approaches include studying damage-induced localization of RecN, its interactions with other RecF pathway proteins, and the genetic consequences of recN disruption on repair proficiency.