Ribbon Style Editor

Ribbon Style Editor allows the cross-sections (shapes) of secondary structure ribbons to be changed. Such ribbons can be displayed using the command ribbon or the Actions menu.

There are several ways to start Ribbon Style Editor, a tool in the Utilities category.

Ribbon Style Editor - default style Starting Ribbon Style Editor opens the editor panel. Changes can be entered directly, or the arrows on either side of a field can be clicked to increase or decrease the value by 0.05-angstrom increments. Only values greater than zero are allowed. Changes will not take effect until either Apply or OK is clicked (OK also dismisses the panel). Of course, changes will not be visible unless a secondary structure ribbon is being displayed. If a ribbon were to be laid out on a flat surface, the Width is the dimension parallel to the surface but perpendicular to the long axis of the ribbon, and the Height is the dimension perpendicular to the surface.

Nucleic acid structures are always shown with a Helix ribbon. For proteins, Helix and Sheet segments are as defined by HELIX and SHEET records in the input file or ksdssp, and the remainder is shown as Turn. Beta strands (the Sheet segments) are shown by default as arrows pointing in the C-terminal direction.

The numerical settings collectively define a ribbon style. These styles can be named, saved, and later retrieved from the pulldown list indicated by the solid black triangle next to the Current Style field. When the name default is shown, it is only possible to save a style to a different name, using Save As.... When another style name is shown, it is possible to

Save the style to the name shown
use Save As... to save the settings to a new style name
Delete the style whose name is shown
Rename... the style whose name is shown

Note that changes, even when applied to the display, are not automatically saved to any style name. Changes are saved only when Save or Save As... is pressed. Ribbon style information is saved in the Chimera preferences file. The style listed as the Current Style at the end of a session will be the starting style for the next session that uses the same preferences file.

Ribbon Style Editor - NOarrow style Setting the Arrow (tip) and Arrow (base) widths the same as the Sheet width turns off the arrow appearance. Setting the Arrow tip and base widths equal to the Turn width also turns off the arrow appearance but shortens the strand somewhat. Setting all the widths equally small generates a simple spaghetti-like representation.

The sharp/edged and smooth/rounded ribbon types are affected by changes in both Width and Height, whereas the flat/ribbon type is only affected by changes in Width (see the ribrepr manual page for a description of the types).

UCSF Computer Graphics Laboratory / December 2002