# BAC, BACKBONE

NAME
BAC, BACKBONE - draw backbone.
SYNOPSIS
BAC
BAC OFF
BAC bond_style
DESCRIPTION
Draw polypeptide (protein) backbone, by connecting neighbouring CA (C alpha) atoms. All other atoms in the selected portion of the structure will be hidden. At present, five bond styles are available, all of them fixed in size.
If this command is specified without any arguments, default bond style (5) will be used.
The command BAC OFF hides the backbone and shows atoms and bonds which were visible before.

STYLE | THICKNESS | TYPE
0 | Invisible bonds | Fixed width.
1 | single, thin line | Fixed width.
2 | Three lines | Fixed width.
3 | Five lines | Fixed width.
4 | Seven lines | Fixed width.
5 | Nine lines | Fixed width.

NOTES
(1) Invisible bonds (style 0) are not treated as hidden - they are just invisible.
RELATED COMMANDS
BON (BONDS) changes drawing style for bonds, but does not affect the backbone. ATO (ATOMS) command may be used to add atoms to the backbone. It is recommended to show only CA atoms, using BALL or SPACEFILL style.