CA-only PDB shown as stick-dots

[Elaine Meng]

I couldn't think of a CA-only structure off the top of my head so I tried opening a structure (1hiv) and deleting all but CAs. At that point it still does show ribbons and missing-segment pseudobonds, as expected. However when I save and reopen it is only disconnected stick-dots, ribbon cannot be shown, and missing-segment pseudobonds exist but appear not to contain anything since show doesn't show any. Attached session with both examples, model #1 after deleting all but CA atoms where it retains biopolymer info, and #2 after saving as PDB and reopening which lost PDB info.

[Tom Goddard]

When I make a CA only 3kz4 in mmCIF format it works correctly, making chains for each subunit.

open 3kz4
delete ~@CA
save 3kz4_CA_only.cif
close
open 3kz4_CA_only.cif

But saving and opening PDB file format does not work, all the atoms are disconnected with no chains. For instance, "rainbow chain" leaves them all one color.

[Eric Pettersen]

85% fixed. Opening the file now shows the dotted backbone and the chain is created. No ribbon is shown and asking for a ribbon shows coil. The written-out file has a 1-residue HELIX record for every residue in a helix. Even with a correct multi-residue HELIX record, it is still all-coil. So fixing that's next.

[Eric Pettersen]

100% fixed.