The Amber simulation systems were prepared with the tleap tool of AmberTools21 . The RNA-protein complex was solvated with a water box with 10Å buffer using 0.15M NaCl solution with SPCE or OPC water model for ff14SB and ff19SB protein force fields, respectively. The ions used parameters specified with the corresponding water model, and the RNA was parameterized with the RNA force field OL3 . To use the larger timestep (4 fs), the hydrogen masses were repartitioned to the connected atoms using ParmEd software .