Hi,

I am using the following code for a tetramer modelling:

from modeller import * from modeller.automodel import * # Load the automodel class log.verbose() class MyModel(automodel): def special_restraints(self, aln): s1 = selection(self.chains['A']).only_atom_types('CA') s2 = selection(self.chains['B']).only_atom_types('CA') s3 = selection(self.chains['C']).only_atom_types('CA') s4 = selection(self.chains['D']).only_atom_types('CA') self.restraints.symmetry.append(symmetry(s1, s2, s3, s4)) def user_after_single_model(self): self.restraints.symmetry.report(1.0)

env = environ() env.io.atom_files_directory = ['.', '../atom_files']

a = MyModel(env, alnfile = 'qseq1-tseq1.ali' , # my alignment filename knowns = 'tseq1', # code of the tetramer template sequence = 'qseq1') # code of the monomer made with modeller

a.starting_model= 1 a.ending_model = 1

a.make()

but after running it, the console is showing "raise KeyError <"No such chain: %s" % indx> KeyError: 'No such chain: A'"

Please help me.

Regards,

Arijit Ghosh