Is it norm with RMSD stabilizing at ~1.1 nm when finishing production mdrun?

GROMACS version: 2021.1
GROMACS modification: No
After finishing 300-ns production mdrun, the RMSD (ref: equilibrated) stabilizing at ~ 1.1 nm as shown below:

Is 1.1 nm is a normal range for my mutated protein? When I search the RMSD range in google and find that mostly the RMSD is less than 1 nm, so I am not sure if my RMSD is OK to use?

Also, for comparison, the wilde-type protein give the RMSD of ~ 0.8 nm, and the shape of “down direct half-circle” looks a little wired for me (I expect it to be stable). Also, at the end time of the simulation, the RMSD falls down suddenly to ~0.6 nm. Do you give some suggestions about this figure? Is it normal to use following structural analysis? Or I need more time to do simulation (but I think 300-ns is already long enough)?

rmsd_0.8 nm_WT_2021-03-28_100834


RMSD is an extrinsic property so there are no rules about what it should be. If you have flexible regions or termini, the value can be artificially inflated.

Bottom line: RMSD tells you very little, if anything, that is useful.

Analyze other structural quantities of interest to see if they are sufficiently converged.

Thanks, Justin. Sure, my protein has a flexible CTD. I will check other metrics.