Effects of 3′-OH and 5′-PO 4 Base Mispairs and Damaged Base Lesions on the Fidelity of Nick Sealing by Deinococcus radiodurans RNA Ligase
| Autor: | Stewart Shuman, Brad J. Schmier |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
DNA Replication
DNA Bacterial Base Sequence biology Stereochemistry Molecular Sequence Data DNA replication RNA Ligase (ATP) RNA Deinococcus radiodurans Articles biology.organism_classification DNA Mismatch Repair Microbiology chemistry.chemical_compound Bacterial Proteins Biochemistry chemistry Nucleic acid Deinococcus Molecular Biology DNA RNA ligase |
| Zdroj: | Journal of Bacteriology. 196:1704-1712 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.00020-14 |
| Popis: | Deinococcus radiodurans RNA ligase (DraRnl) is the founding member of a family of end-joining enzymes encoded by diverse microbes and viruses. DraRnl ligates 3′-OH, 5′-PO 4 nicks in double-stranded nucleic acids in which the nick 3′-OH end is RNA. Here we gauge the effects of 3′-OH and 5′-PO 4 base mispairs and damaged base lesions on the rate of nick sealing. DraRnl is indifferent to the identity of the 3′-OH nucleobase, provided that it is correctly paired. With 3′-OH mispairs, the DraRnl sealing rate varies widely, with G-T and A-C mispairs being the best substrates and G-G, G-A, and A-A mispairs being the worst. DraRnl accepts 3′ A–8-oxoguanine (oxoG) to be correctly paired, while it discriminates against U-oxoG and G-oxoG mispairs. DraRnl displays high activity and low fidelity in sealing 3′-OH ends opposite an 8-oxoadenine lesion. It prefers 3′-OH adenosine when sealing opposite an abasic template site. With 5′-PO 4 mispairs, DraRnl seals a 5′ T-G mispair as well as it does a 5′ C-G pair; in most other respects, the ligation fidelity at 5′ mispairs is similar to that at 3′ mispairs. DraRnl accepts a 5′ A-oxoG end to be correctly paired, yet it is more tolerant of 5′ T-oxoG and 5′ G-oxoG mispairs than the equivalent configurations on the 3′ side of the nick. At 5′ nucleobase-abasic site nicks, DraRnl prefers to ligate when the nucleobase is a purine. The biochemical properties of DraRnl are compatible with its participation in the templated repair of RNA damage or in the sealing of filled DNA gaps that have a 3′ ribopatch. |
| Databáze: | OpenAIRE |
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