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Updated: Sep 11, 2025
06:48
CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
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AlkD's Conformational Dynamics Regulated by Protein-DNA Interactions for Effective Target Recognition
Yanping Qi1,2, Jiaxin Guo3, Xiaowei Wang4
1State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
The Journal of Physical Chemistry Letters
|August 12, 2025
Summary
Bacillus cereus alkylpurine DNA glycosylase (AlkD) uses unique mechanisms to find and remove DNA lesions. Key residues W109 and R148 are crucial for its selectivity towards positively charged DNA damage.
Area of Science:
- Biochemistry
- Molecular Biology
- Genomics
Background:
- Bacillus cereus alkylpurine DNA glycosylase (AlkD) repairs DNA damage, particularly cytotoxic positively charged lesions.
- AlkD utilizes a unique non-base-flipping mechanism with distinct conformational states for DNA searching and lesion excision.
Purpose of the Study:
- To investigate the lesion recognition mechanism of the AlkD-dsDNA complex.
- To elucidate the interplay between AlkD's conformational dynamics and its lesion recognition capabilities.
Main Methods:
- Microsecond-scale molecular dynamics (MD) simulations.
- Scanning fluorescence resonance energy transfer-fluorescence correlation spectroscopy (FRET-FCS) experiments.
- Cellular assays.
Main Results:
- Identified critical residues W109 and R148 as molecular probes for DNA lesion and mismatch recognition.
- Demonstrated that W109 and R148 alter the equilibrium between search complex (SC) and excision complex (EC) states.
- Showed enhanced recognition by W109 and R148 for positively charged lesions, explaining AlkD's selectivity.
Conclusions:
- AlkD's conformational dynamics and residue-specific interactions are key to its DNA repair function.
- Residues W109 and R148 play a vital role in AlkD's target search and selective lesion recognition.
- Provides molecular insights into the DNA repair mechanism of AlkD.
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