ANG, ANGLE
NAME
ANG, ANGLE - set angle.
SYNOPSIS
ANG value
ANGLE value
DESCRIPTION
Set the rotation angle between adjacent residues. This angle is stored as an
internal variable and used to draw helical wheel or hydrophobic moment plot.
The value should be specified in degrees. Default value is 100 degrees,
which corresponds to alpha helix rotation angle. To prepare helical wheel or
hydrophobic moment plot you have to make the assumption about the secondary
structure. The assumption is made by setting the rotation angle for adjacent
residues. The table below lists the common structural motifs and the
corresponding angles.
STRUCTURAL
MOTIF
|
RESIDUES
PER TURN
|
ANGLE
(DEGREES)
|
|
alpha helix
|
3.6
|
100
|
|
3-10 helix
|
3
|
120
|
|
beta strand
|
2.3
|
160
|
3-10 helices are usually short, but if you assume that more than three
residues fold into 3-10 helix, modify the angle used to draw the helical wheel.
If you use the realistic angle (120 degrees), some residues will be obscured
(hidden behind the residues which are drawn later). Use 115 or 125 instead of
120 degrees, to avoid overlapping of residues.
RELATED COMMANDS
WHEEL draws the helical wheel. PLOT draws the hydrophobic moment plot.