1s10
Snapshots of replication through an abasic lesion: structural basis for base substitution and frameshiftSnapshots of replication through an abasic lesion: structural basis for base substitution and frameshift
Structural highlights
FunctionDPO4_SACS2 Poorly processive, error-prone DNA polymerase involved in untargeted mutagenesis. Copies undamaged DNA at stalled replication forks, which arise in vivo from mismatched or misaligned primer ends. These misaligned primers can be extended by PolIV. Exhibits no 3'-5' exonuclease (proofreading) activity. It is involved in translesional synthesis. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDpo4 from S. Solfataricus, a DinB-like Y family polymerase, efficiently replicates DNA past an abasic lesion. We have determined crystal structures of Dpo4 complexed with five different abasic site-containing DNA substrates and find that translesion synthesis is template directed with the abasic site looped out and the incoming nucleotide is opposite the base 5' to the lesion. The ensuing DNA synthesis generates a -1 frameshift when the abasic site remains extrahelical. Template realignment during primer extension is also observed, resulting in base substitutions or even +1 frameshifts. In the case of a +1 frameshift, the extra nucleotide is accommodated in the solvent-exposed minor groove. In addition, the structure of an unproductive Dpo4 ternary complex suggests that the flexible little finger domain facilitates DNA orientation and translocation during translesion synthesis. Snapshots of replication through an abasic lesion; structural basis for base substitutions and frameshifts.,Ling H, Boudsocq F, Woodgate R, Yang W Mol Cell. 2004 Mar 12;13(5):751-62. PMID:15023344[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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