pdb-mode is an emacs-lisp minor mode for Emacs to perform a number of useful editing functions on Protein DataBank (PDB) formatted files. XEmacs and/or GNU Emacs are available for most computing platforms.
Read more on implemented functions https://crystal.scb.uwa.edu.au/charlie/software/pdb-mode/
(@mmagnus: I'm not an author of this code, I just updated it slightly, fixed it in 2020, all credits go to Charlie Bond & David Love, I asked Charles S. Bond if I can share it and he was OK with that ;-)
Re-tested 2022:
- Select with Emacs a modified reside and "Convert HETATM -> ATOM"