期刊
JOURNAL OF BIOLOGICAL CHEMISTRY
卷 289, 期 9, 页码 5938-5949出版社
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M113.530741
关键词
ATPases; DNA Repair; DNA-Protein Interaction; Molecular Motors; Protein Conformation; Recombination; Structure
资金
- Human Frontier Science Program Grant [RGY0072/2010]
- Momentum Program of the Hungarian Academy of Sciences Grant [LP2011-006/2011]
- European Union
- European Social Fund [TAMOP 4.2.4.A/1-11-1-2012-0001]
- State of Hungary
Background: The mechanistic role of DNA-induced structural changes in RecQ helicases is largely unexplored. Results: DNA interaction of RecQ helicase depends on the nucleotide state of the enzyme and the presence of an intact HRDC domain. Conclusion: We identified a structural transition of the RecQ-DNA complex that is linked to the mechanoenzymatic cycle. Significance: This transition contributes to translocation along DNA and genome-maintaining activities. The allosteric communication between the ATP- and DNA-binding sites of RecQ helicases enables efficient coupling of ATP hydrolysis to translocation along single-stranded DNA (ssDNA) and, in turn, the restructuring of multistranded DNA substrates during genome maintenance processes. In this study, we used the tryptophan fluorescence signal of Escherichia coli RecQ helicase to decipher the kinetic mechanism of the interaction of the enzyme with ssDNA. Rapid kinetic experiments revealed that ssDNA binding occurs in a two-step mechanism in which the initial binding step is followed by a structural transition of the DNA-bound helicase. We found that the nucleotide state of RecQ greatly influences the kinetics of the detected structural transition, which leads to a high affinity DNA-clamped state in the presence of the nucleotide analog ADP-AlF4. The DNA binding mechanism is largely independent of ssDNA length, indicating the independent binding of RecQ molecules to ssDNA and the lack of significant DNA end effects. The structural transition of DNA-bound RecQ was not detected when the ssDNA binding capability of the helicase-RNase D C-terminal domain was abolished or the domain was deleted. The results shed light on the nature of conformational changes leading to processive ssDNA translocation and multistranded DNA processing by RecQ helicases.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据