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Regulation of UvrD Helicase Activity by MutL.
Yerdos A Ordabayev1, Binh Nguyen1, Anita Niedziela-Majka1
1Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., Box 8231, St. Louis, MO 63110, United States.
Journal of Molecular Biology
|September 2, 2018
Summary
Escherichia coli MutL protein activates the helicase activity of UvrD, a key enzyme in DNA repair. MutL enhances UvrD
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Escherichia coli UvrD is a superfamily 1 helicase/translocase essential for DNA repair pathways.
- UvrD requires dimerization for efficient processive helicase activity.
- E. coli MutL is a regulatory protein implicated in methyl-directed mismatch repair, known to stimulate UvrD activity.
Purpose of the Study:
- To elucidate the mechanism by which E. coli MutL stimulates UvrD helicase activity.
- To investigate the role of MutL in modulating UvrD's DNA unwinding processivity.
Main Methods:
- Single-molecule fluorescence assays.
- Ensemble biochemical assays.
Main Results:
- A single MutL dimer activates latent UvrD monomer helicase activity.
- MutL also stimulates UvrD dimer helicase activity.
- MutL significantly enhances the DNA-unwinding processivity of UvrD.
Conclusions:
- MutL functions as a processivity factor for UvrD.
- MutL likely binds to and moves with UvrD, facilitating DNA unwinding.
- This interaction is crucial for efficient DNA repair mechanisms involving UvrD.
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