Hi,
Thanks for your question regarding SNAP's applicability to RNA-protein structures. Yes, SNAP can be used for RNA-protein complexes as well as DNA-protein complexes, by specifying explicitly the --rna option. Given the complexities of nucleic-acids/proteins interactions, I've intended to start SNAP with DNA-protein structures. Since this question has been brought up several times (both in the Forum and privately), here is the response. Note that in the future, the --rna option may be removed from SNAP when the functionality becomes default.
Move functionality is being added to SNAP, and a new release is coming out soon. As always, please do not hesitate to ask any SNAP-related questions on the Forum.
Xiang-Jun