Can We Execute Stable Microsecond-Scale Atomistic Simulations of Protein-RNA Complexes?
M Krepl1, M Havrila1, P Stadlbauer1
1Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.
Journal of Chemical Theory and Computation
|November 19, 2015
Summary
Molecular dynamics simulations reveal protein-RNA complex stability varies greatly. Shape-specific recognition leads to more stable complexes than sequence-specific recognition, highlighting individual system challenges.
Area of Science:
- Biophysics
- Computational Biology
- Structural Biology
Background:
- Protein-RNA complexes are crucial for cellular function.
- Accurate simulation of these complexes is vital for understanding their dynamics and interactions.
- Existing computational models face challenges in capturing the stability and behavior of diverse protein-RNA systems.
Purpose of the Study:
- To investigate the stability and behavior of six protein-RNA complexes using extensive molecular dynamics (MD) simulations.
- To evaluate the performance of different molecular mechanics force fields (AMBER ff99bsc0χ(OL3) for RNA and ff99SB/ff12SB for proteins) in simulating these systems.
- To identify factors influencing the stability of simulated protein-RNA complexes.
Main Methods:
- Conducted over 30 microseconds of unrestrained molecular dynamics simulations in explicit solvent.
- Employed the AMBER ff99bsc0χ(OL3) RNA force field and the ff99SB and ff12SB protein force fields.
- Analyzed simulation trajectories for structural stability, deviations from experimental structures, and factors affecting behavior.
Main Results:
- Simulations exhibited variable stability, with some systems deviating significantly from experimental structures.
- Microsecond-scale simulations were necessary for stabilization after initial structural perturbations.
- Structural stability did not correlate with buried surface area or binding affinity but was linked to the type of RNA recognition (shape-specific vs. sequence-specific).
- The ff12SB force field showed improved tyrosine side-chain dynamics compared to ff99SB.
Conclusions:
- Simulating protein-RNA complexes is challenging and requires individualized approaches.
- The type of protein-RNA recognition mechanism significantly impacts complex stability in simulations.
- Force field choice and starting structure quality are critical factors, with system-specific properties dominating simulation outcomes.
