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Excision of uracil from DNA by hSMUG1 includes strand incision and processing
- Source :
- Alexeeva, M, Moen, M N, Grøsvik, K, Tesfahun, A N, Xu, X M, Muruzábal-Lecumberri, I, Olsen, K M, Rasmussen, A, Ruoff, P, Kirpekar, F, Klungland, A & Bjelland, S 2019, ' Excision of uracil from DNA by hSMUG1 includes strand incision and processing ', Nucleic Acids Research, vol. 47, no. 2, pp. 779-793 . https://doi.org/10.1093/nar/gky1184, Nucleic Acids Research
- Publication Year :
- 2018
- Publisher :
- Oxford University Press, 2018.
-
Abstract
- Uracil arises in DNA by hydrolytic deamination of cytosine (C) and by erroneous incorporation of deoxyuridine monophosphate opposite adenine, where the former event is devastating by generation of C → thymine transitions. The base excision repair (BER) pathway replaces uracil by the correct base. In human cells two uracil-DNA glycosylases (UDGs) initiate BER by excising uracil from DNA; one is hSMUG1 (human single-strand-selective mono-functional UDG). We report that repair initiation by hSMUG1 involves strand incision at the uracil site resulting in a 3′-α,β-unsaturated aldehyde designated uracil-DNA incision product (UIP), and a 5′-phosphate. UIP is removed from the 3′-end by human apurinic/apyrimidinic (AP) endonuclease 1 preparing for single-nucleotide insertion. hSMUG1 also incises DNA or processes UIP to a 3′-phosphate designated uracil-DNA processing product (UPP). UIP and UPP were indirectly identified and quantified by polyacrylamide gel electrophoresis and chemically characterised by matrix-assisted laser desorption/ionisation time-of-flight mass-spectrometric analysis of DNA from enzyme reactions using 18O- or 16O-water. The formation of UIP accords with an elimination (E2) reaction where deprotonation of C2′ occurs via the formation of a C1′ enolate intermediate. A three-phase kinetic model explains rapid uracil excision in phase 1, slow unspecific enzyme adsorption/desorption to DNA in phase 2 and enzyme-dependent AP site incision in phase 3.
- Subjects :
- DNA Repair
Stereochemistry
Deamination
Biology
Genome Integrity, Repair and Replication
03 medical and health sciences
chemistry.chemical_compound
0302 clinical medicine
Genetics
Humans
AP site
DNA Cleavage
Uracil
Uracil-DNA Glycosidase
030304 developmental biology
0303 health sciences
Temperature
Base excision repair
DNA
Thymine
Kinetics
chemistry
DNA glycosylase
030217 neurology & neurosurgery
Cytosine
Subjects
Details
- ISSN :
- 03051048
- Database :
- OpenAIRE
- Journal :
- Alexeeva, M, Moen, M N, Grøsvik, K, Tesfahun, A N, Xu, X M, Muruzábal-Lecumberri, I, Olsen, K M, Rasmussen, A, Ruoff, P, Kirpekar, F, Klungland, A & Bjelland, S 2019, ' Excision of uracil from DNA by hSMUG1 includes strand incision and processing ', Nucleic Acids Research, vol. 47, no. 2, pp. 779-793 . https://doi.org/10.1093/nar/gky1184, Nucleic Acids Research
- Accession number :
- edsair.doi.dedup.....75365a8bc8f013d98f4a9e88573fb64b