Chimera Commands Index

ribbackbone  atom-spec

~ribbackbone  atom-spec

By default, when ribbon is shown, mainchain atoms (backbone atoms) are hidden and their locations are adjusted to fall on the ribbon. The ribbon residue class determines which atoms are considered mainchain. The amino acid and nucleic acid classes are built into Chimera, but additional classes can be created with Ribbon Style Editor.

Ribbackbone allows displaying backbone atoms at their unadjusted positions at the same time as ribbon (of course, these atoms can still be undisplayed). ~Ribbackbone restores the default behavior. If the atom-spec is blank, all open molecule models will be affected; otherwise, the entire model(s) containing atom-spec will be affected. Whether ribbon and backbone atoms can be displayed simultaneously for residues within a model can also be controlled in the molecule model attributes panel.

The ribbon follows a smooth, interpolated path that in some places may not overlap well with the backbone atoms. Displayed in their true positions, these atoms may appear to be “floating” away from the ribbon. The method of path calculation can be controlled with ribspline; a cardinal spline may be preferred over the default B-spline for more closely tracking the backbone atom positions (more...).

See also: ribbon, ribrepr, ribscale, ribclass, ribspline, display