Bartlett_Ribonucleoltic_resection_2013.pdf (5.94 MB)
Ribonucleolytic resection is required for repair of strand displaced nonhomologous end-joining intermediates
journal contribution
posted on 2023-06-08, 16:26 authored by Edward Bartlett, Nigel Brissett, Aidan DohertyAidan DohertyNonhomologous end-joining (NHEJ) pathways repair DNA double-strand breaks (DSBs) in eukaryotes and many prokaryotes, although it is not reported to operate in the third domain of life, archaea. Here, we describe a complete NHEJ complex, consisting of DNA ligase (Lig), polymerase (Pol), phosphoesterase (PE), and Ku from a mesophillic archaeon, Methanocella paludicola (Mpa). Mpa Lig has limited DNA nick-sealing activity but is efficient in ligating nicks containing a 3' ribonucleotide. Mpa Pol preferentially incorporates nucleoside triphosphates onto a DNA primer strand, filling DNA gaps in annealed breaks. Mpa PE sequentially removes 3' phosphates and ribonucleotides from primer strands, leaving a ligatable terminal 3' monoribonucleotide. These proteins, together with the DNA end-binding protein Ku, form a functional NHEJ break-repair apparatus that is highly homologous to the bacterial complex. Although the major roles of Pol and Lig in break repair have been reported, PE’s function in NHEJ has remained obscure. We establish that PE is required for ribonucleolytic resection of RNA intermediates at annealed DSBs. Polymerase-catalyzed strand-displacement synthesis on DNA gaps can result in the formation of nonligatable NHEJ intermediates. The function of PE in NHEJ repair is to detect and remove inappropriately incorporated ribonucleotides or phosphates from 3' ends of annealed DSBs to configure the termini for ligation. Thus, PE prevents the accumulation of abortive genotoxic DNA intermediates arising from strand displacement synthesis that otherwise would be refractory to repair.
History
Publication status
- Published
File Version
- Accepted version
Journal
Proceedings of the National Academy of SciencesISSN
1091-6490Publisher
National Academy of SciencesExternal DOI
Issue
22Volume
110Article number
E1984-E1991Department affiliated with
- Sussex Centre for Genome Damage Stability Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2013-11-28First Open Access (FOA) Date
2013-11-28First Compliant Deposit (FCD) Date
2013-11-28Usage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC