[gmx-users] selection of pulling region

[jinxin]

hello！ everyone， i want to perform the smd of my protein-protein interactions systmes. however, i don't know how to select the region of pulling. should i select the COM (center of mass) of one protein, only a atom，COM of some residues or the COM of a domian of the protien? What kind of effect on the results with diffrent selection of pulling region?
    thank you very much!