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Exploring the RNA-bound and RNA-free human Argonaute-2 by molecular dynamics simulation method
Ren Kong1, Lei Xu1, Lianhua Piao1
1School of Electrical and Information Engineering, Institute of Bioinformatics and Medical Engineering, Jiangsu University of Technology, Changzhou, China.
Chemical Biology & Drug Design
|April 8, 2017
Summary
Argonaute 2 (Ago2) protein dynamics reveal crucial RNA interactions. The PAZ domain
Area of Science:
- Molecular Biology
- Structural Biology
- Biochemistry
Background:
- Argonaute 2 (Ago2) is central to microRNA (miRNA)-guided gene silencing.
- The static crystal structure of human Ago2 (hAgo2) is known, but its dynamic RNA recognition mechanisms remain unclear.
Purpose of the Study:
- To investigate the dynamic structural character of protein-RNA recognition in hAgo2.
- To elucidate the role of specific domains and interactions in hAgo2-mediated gene regulation.
Main Methods:
- Utilized molecular dynamics simulations to analyze hAgo2 in the presence and absence of RNA duplex.
- Observed hydrogen bonding patterns and domain movements during simulations.
Main Results:
- Identified stable direct and water-mediated hydrogen bonds between guide RNA and hAgo2, particularly nucleotides 2-7.
- Highlighted the critical role of water-mediated hydrogen bonds in recognizing the conserved adenine at target RNA position 1.
- Observed rigid body movements in core domains (N, PAZ, MID, PIWI), with the PAZ domain exhibiting the highest mobility.
- Found negatively correlated motions between N-PAZ and PIWI-MID domains, with or without RNA binding.
- Demonstrated PAZ domain reorientation influencing initial RNA duplex binding and supplemental base pairing.
Conclusions:
- PAZ domain dynamics are critical for hAgo2 function in miRNA-guided gene regulation.
- Specific hydrogen bonding interactions, including water-mediated ones, are key to hAgo2-RNA recognition.
- The dynamic interplay of hAgo2 domains, particularly PAZ, regulates the miRNA-induced gene silencing process.