Effects of DNA3 'pp5 'G capping on 3 ' end repair reactions and of an embedded pyrophosphate-linked guanylate on ribonucleotide surveillance Journal Article


Authors: Chauleau, M.; Das, U.; Shuman, S.
Article Title: Effects of DNA3 'pp5 'G capping on 3 ' end repair reactions and of an embedded pyrophosphate-linked guanylate on ribonucleotide surveillance
Abstract: When DNA breakage results in a 3′-PO<inf>4</inf> terminus, the end is considered 'dirty' because it cannot prime repair synthesis by DNA polymerases or sealing by classic DNA ligases. The noncanonical ligase RtcB can guanylylate the DNA 3′-PO<inf>4</inf> to form a DNA<inf>3′</inf>pp<inf>5′</inf>G<inf>OH</inf> cap. Here we show that DNA capping precludes end joining by classic ATP-dependent and NAD+-dependent DNA ligases, prevents template-independent nucleotide addition by mammalian terminal transferase, blocks exonucleolytic proofreading by Escherichia coli DNA polymerase II and inhibits proofreading by E. coli DNA polymerase III, while permitting templated DNA synthesis from the cap guanosine 3′-OH primer by E. coli DNA polymerase II (B family) and E. coli DNA polymerase III (C family). Human DNA polymerase β (X family) extends the cap primer predominantly by a single templated addition step. Cap-primed synthesis by templated polymerases embeds a pyrophosphate-linked ribonucleotide in DNA. We find that the embedded ppG is refractory to surveillance and incision by RNase H2. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.
Journal Title: Nucleic Acids Research
Volume: 43
Issue: 6
ISSN: 0305-1048
Publisher: Oxford University Press  
Date Published: 2015-03-31
Start Page: 3197
End Page: 3207
Language: English
DOI: 10.1093/nar/gkv179
PROVIDER: scopus
PMCID: PMC4381079
PUBMED: 25753667
DOI/URL:
Notes: Export Date: 2 October 2015 -- Source: Scopus
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  1. Stewart H Shuman
    546 Shuman
  2. Ushati Das
    11 Das