title: The key residue for SSB-RecO interaction is dispensable for Deinococcus radiodurans DNA repair in vivo.
abstract: The RecFOR DNA repair pathway is one of the major RecA-dependent recombinatorial repair pathways in bacteria and plays an important role in double-strand breaks repair. RecO, one of the major recombination mediator proteins in the RecFOR pathway, has been shown to assist RecA loading onto single-stranded binding protein (SSB) coated single-stranded DNA (ssDNA). However, it has not been characterized whether the protein-protein interaction between RecO and SSB contributes to that process in vivo. Here, we identified the residue arginine-121 of Deinococcus radiodurans RecO (drRecO-R121) as the key residue for RecO-SSB interaction. The substitution of drRecO-R121 with alanine greatly abolished the binding of RecO to SSB but not the binding to RecR. Meanwhile, SSB-coated ssDNA annealing activity was also compromised by the mutation of the residue of drRecO. However, the drRecO-R121A strain showed only modest sensitivity to DNA damaging agents. Taking these data together, arginine-121 of drRecO is the key residue for SSB-RecO interaction, which may not play a vital role in the SSB displacement and RecA loading process of RecFOR DNA repair pathway in vivo.
authors.affiliation: Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China.
authors.forename: Kaiying
authors.initials: K
authors.lastname: Cheng
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhao
authors.forename: Liangyan
authors.initials: L
authors.lastname: Wang
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Xu
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Hua
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D001483:Base Sequence; D017931:DNA Primers; D004260:DNA Repair; D034301:Deinococcus / Q000502:physiology*; D024202:Electrophoretic Mobility Shift Assay
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers
keywords: DNA repair; Deinococcus radiodurans; RecFOR; RecO; single-stranded binding protein