CYANA Command: angles set

Parameters

selection=string

(default: <blank>)

value=string

(default: <blank>)

free

fixed

rigid

cis

trans

Description

Command to set properties of the torsion angles that match the selection string. By default, the selection made in the most recent angles select' command is used, or all angles if no selection has been made so far.

The value of a torsion angle can be set with the parameter value. The string is a real number or a real expression that may contain the symbol value to represent the current value of the torsion angle. Torsion angle values are given in degrees.

Torsion angles are fixed to their current value if the option fixed is given. Fixed torsion angles are non-rotatable and cannot be changed during minimization or torsion angle dynamics.

Torsion angles are made rotatable if the option free is given. Free torsion angles can be changed during minimization or torsion angle dynamics.

Initially, all torsion angles defined in the library are rotatable except for those called OMEGA, which are typically used for the peptide bonds in polypeptides. OMEGA angles are fixed to 180 degrees (trans). Optionally, the OMEGA angle preceding a given amino acid residue can be fixed to 0 degrees (cis) by a preceding the residue name in the sequence (.seq) file by a lowercase 'c'.