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-Structure paper
タイトル | Self-correcting mismatches during high-fidelity DNA replication. |
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ジャーナル・号・ページ | Nat Struct Mol Biol, Vol. 24, Issue 2, Page 140-143, Year 2017 |
掲載日 | 2017年1月9日 |
著者 | Rafael Fernandez-Leiro / Julian Conrad / Ji-Chun Yang / Stefan M V Freund / Sjors H W Scheres / Meindert H Lamers / |
PubMed 要旨 | Faithful DNA replication is essential to all forms of life and depends on the action of 3'-5' exonucleases that remove misincorporated nucleotides from the newly synthesized strand. However, how the ...Faithful DNA replication is essential to all forms of life and depends on the action of 3'-5' exonucleases that remove misincorporated nucleotides from the newly synthesized strand. However, how the DNA is transferred from the polymerase to the exonuclease active site is not known. Here we present the cryo-EM structure of the editing mode of the catalytic core of the Escherichia coli replisome, revealing a dramatic distortion of the DNA whereby the polymerase thumb domain acts as a wedge that separates the two DNA strands. Importantly, NMR analysis of the DNA substrate shows that the presence of a mismatch increases the fraying of the DNA, thus enabling it to reach the exonuclease active site. Therefore the mismatch corrects itself, whereas the exonuclease subunit plays a passive role. Hence, our work provides unique insights into high-fidelity replication and establishes a new paradigm for the correction of misincorporated nucleotides. |
リンク | Nat Struct Mol Biol / PubMed:28067916 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 6.7 Å |
構造データ | EMDB-4141, PDB-5m1s: EMDB-4142: |
由来 |
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キーワード | DNA BINDING PROTEIN / DNA editing Proofreading Exonuclease Polymerase |