DNA nonhomologous end-joining (NHEJ) system in prokaryotes

Mehanizmi popravka lomova DNA su detaljno proučavani zbog svoje važnosti na vijabilnost svih organizama u prirodi i njihovu genetičku stabilnost. Dva su najvažnija puta popravka lomova DNA; homologna rekombinacija (uz nisku stopu pogreške) te nehomologno spajanje krajeva (često popraćeno mutacijama). Opisan je sam model nehomolognog popravka koji uključuje dva najvažnija enzima, a to su protein Ku i ligaza LigD, koji stvaraju kompleks s dvolančanim lomovima DNA. Ligaza LigD ima tri katalitičke aktivnosti (polimeraznu, ligaznu i fosfoesteraznu) koje djeluju u popravljanju lomova. Međutim, nije sasvim sigurno jesu li ova dva proteina jedini uključeni u popravak.DNA repair pathways of broken DNA have been intensely studied because of their importance for organism viability and genome integrity. The most important two pathways for repairing broken DNA are homologous recombination (error free) and nonhomologous end joining (error prone). Nonhomologous pathway includes two significant factors; Ku protein and LigD ligase that form a complex with DNA double strand breaks. LigD ligase has three catalytic activities (polimerase, ligase and phosphoesterase) that participate in the repair. However, it is not completely clear if these two proteins are the only participants in this repair mechanism