I've got some PDB files that I have converted from a GROMACS structure and trajectory file that has resName values with 4 characters in them, but the houdini PDB import strips that back to 3 characters. Is there a way to get Houdini to give me the full 4 characters with the default importer? There are some different residues that end up looking the same when shortened to 3 characters.

I've created a python importer for both the gromacs structre & trajectory files to import directly which gives me the 4 characters, but running through python and MDAnalysis is ridiculously slow, as is the python importer for PDB that I made. The python importer for PDB that I made shows 4 characters too, but as mentioned is very slow.

Four character residue names are non-standard - according to the specification, the residue name is three characters long. Unfortunately there currently isn't a way to import data with four characters.

Perhaps you can massage your data into a format where your four character names are mapped to a unique three character name?

https://www.cgl.ucsf.edu/chimera/docs/UsersGuide/tutorials/pdbintro.html [www.cgl.ucsf.edu]

Thanks for the clarification John. I've done some massaging with a prior project using python, so that's definitely something I can do. I was hoping to avoid yet-another stage of conversion but if its my only way to do it then its the way I'll do it!