[Biopython] Bio.PDB local MMCIF files

[Dave Howorth]

I'm just looking at Bio.PDB with a view to switching over to it, so I
can use it to read MMCIF files in preparation for 4-character chain IDs
etc. I presently use a homegrown perl module to read PDB files, and I
have a local PDB mirror. I see from

http://biopython.org/wiki/The_Biopython_Structural_Bioinformatics_FAQ

that there's some sort of facility to use local files, perhaps using
PDBList() but I don't see from the FAQ or the PDBList class docs exactly
which directory it wants and whether it is PDB files only or a complete
archive. The only hints seem to hint at a single directory of PDB files
or a divided directory hierarchy of PDB files, neither of which will
contain the MMCIF files. So is it:

/$TOP/data
/$TOP/data/structures
/$TOP/data/structures/all

Or is it some other technique entirely to access MMCIF files?

Looking at the code, it seems to want a full path to an MMCIF file, and
the MMCIF file must be uncompressed. Since all the files in the archive
are compressed, that would be another thing I'd want to fix.

Oh, I'm currently using the V1.58 that came with the machine I'm testing
on. I can upgrade if essential.

Thanks and regards,
Dave