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Mechanism of hRev1 polymerase action on G‐quadruplex DNA (927.3)
Author(s) -
Eddy Sarah,
Zafar Maroof,
Ketkar Amit,
Maddukuri Leena,
Eoff Robert
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.927.3
Subject(s) - dna replication , footprinting , dna footprinting , polymerase , dna , telomere , dna polymerase , biology , replisome , microbiology and biotechnology , mechanism of action , chemistry , eukaryotic dna replication , genetics , biochemistry , dna binding protein , gene , transcription factor , in vitro , base sequence
Faithful replication of genomic information is crucial for maintenance of cellular function and integrity. DNA can adopt non‐B‐form structures in vivo, such as stable G‐quadruplex DNA (QDNA). The accurate replication of QDNA is important, as these structures regulate transcription of oncogenes and telomere dynamics. Recent studies have implicated Rev1 polymerase in successful QDNA replication. We hypothesized that human Rev1 might help maintain fork progress at QDNA sites because of its unique protein template‐directed mechanism of DNA replication and sought to investigate the hRev1 biochemical mechanism of action on QDNA substrates. We find that hRev1 preferentially binds to QDNA substrates. hRev1 is able to catalyze dCMP insertion, but the efficiency of nucleotidyl transfer is impaired opposite tetrad‐guanines. Results from dimethyl sulfate footprinting and stopped‐flow fluorescence assays are consistent with the notion that hRev1 can disrupt QDNA structures without performing nucleotidyl transfer. The specific molecular features that allow hRev1 to bind and disrupt QDNA are the subject of ongoing experiments. In conclusion, our study has identified new properties related to the functional and mechanistic role assumed by hRev1 in QDNA replication. Grant Funding Source : Supported in part by USPHS R00 GM084460 (R.L.E.)