2 research outputs found
Identification of a conserved 5′-dRP lyase activity in bacterial DNA repair ligase D and its potential role in base excision repair
Bacillus subtilis is one of the bacterial members
provided with a nonhomologous end joining (NHEJ)
system constituted by the DNA-binding Ku homodimer
that recruits the ATP-dependent DNA Ligase
D (BsuLigD) to the double-stranded DNA breaks
(DSBs) ends. BsuLigD has inherent polymerization
and ligase activities that allow it to fill the short
gaps that can arise after realignment of the broken
ends and to seal the resulting nicks, contributing
to genome stability during the stationary phase and
germination of spores. Here we show that BsuLigD
also has an intrinsic 5'-2-deoxyribose-5-phosphate
(dRP) lyase activity located at the N-terminal ligase
domain that in coordination with the polymerization
and ligase activities allows efficient repairing of 2'-
deoxyuridine-containing DNA in an in vitro reconstituted
Base Excision Repair (BER) reaction. The requirement
of a polymerization, a dRP removal and
a final sealing step in BER, together with the joint
participation of BsuLigD with the spore specific AP
endonuclease in conferring spore resistance to ultrahigh
vacuum desiccation suggest that BsuLigD
could actively participate in this pathway.We demonstrate
the presence of the dRP lyase activity also in
the homolog protein from the distantly related bacterium
Pseudomonas aeruginosa, allowing us to expand
our results to other bacterial LigDs