Grouping DNA and protein for RMSD calculations

GROMACS version: 20202
GROMACS modification: No

I would like to perform RMSD calculations for protein-DNA complex in my simulation in order to check the stability of the protein-DNA complex.

How do I group both DNA and protein into one group so that I can perform RMSD analysis using make_ndx.

How do I proceed with this?

Thank you in advance

Hi,

If you want to compute the RMSD of the CA and/or backbone atoms of the protein (only) interacting with the DNA use 3 ou 4.