This is a read-only mirror of pymolwiki.org

Difference between revisions of "Pse export version"

From PyMOL Wiki
Jump to navigation Jump to search
(Replaced content with "Find polar pairs")
Line 1: Line 1:
Find polar pairs with the [[find_pairs|cmd.find_pairs]] function and return them as a list of atom pairs. It finds (more or less) the same contacts like [[distance|cmd.distance(mode=2)]].
+
Find polar pairs
 
 
== Example ==
 
 
 
<source lang="python">
 
pairs = polarpairs('chain A', 'chain B')
 
for p in pairs:
 
    dist = cmd.get_distance('(%s`%s)' % p[0], '(%s`%s)' % p[1])
 
    print p, 'Distance: %.2f' % (dist)
 
</source>
 
 
 
== The Script ==
 
 
 
<source lang="python">
 
'''
 
(c) 2011 Thomas Holder, MPI for Developmental Biology
 
'''
 
 
 
from pymol import cmd
 
 
 
def polarpairs(sel1, sel2, cutoff=4.0, angle=63.0, name='', state=1, quiet=1):
 
    '''
 
ARGUMENTS
 
 
 
    sel1, sel2 = string: atom selections
 
 
 
    cutoff = float: distance cutoff
 
 
 
    angle = float: h-bond angle cutoff in degrees. If angle="default", take
 
    "h_bond_max_angle" setting. If angle=0, do not detect h-bonding.
 
 
 
    name = string: If given, also create a distance object for visual representation
 
 
 
SEE ALSO
 
 
 
    cmd.find_pairs, cmd.distance
 
    '''
 
    cutoff = float(cutoff)
 
    quiet = int(quiet)
 
    state = int(state)
 
    if angle == 'default':
 
        angle = cmd.get('h_bond_max_angle', cmd.get_object_list(sel1)[0])
 
    angle = float(angle)
 
    mode = 1 if angle > 0 else 0
 
    x = cmd.find_pairs('(%s) and donors' % sel1, '(%s) and acceptors' % sel2,
 
            state, state,
 
            cutoff=cutoff, mode=mode, angle=angle) + \
 
        cmd.find_pairs('(%s) and acceptors' % sel1, '(%s) and donors' % sel2,
 
            state, state,
 
            cutoff=cutoff, mode=mode, angle=angle)
 
    x = sorted(set(x))
 
    if not quiet:
 
        print 'Settings: cutoff=%.1fangstrom angle=%.1fdegree' % (cutoff, angle)
 
        print 'Found %d polar contacts' % (len(x))
 
    if len(name) > 0:
 
        for p in x:
 
            cmd.distance(name, '(%s`%s)' % p[0], '(%s`%s)' % p[1])
 
    return x
 
 
 
cmd.extend('polarpairs', polarpairs)
 
</source>
 
 
 
[[Category:Plugins]]
 
[[Category:Biochemical_Scripts]]
 

Revision as of 20:26, 23 April 2015

Find polar pairs