CD task4 protocol

Modeller

We modified the scripts provided in the tutorial to suit our demands.

Target

The sequence of out target Aspartoacylase saved in .pir format:

>P1;p45381
sequence:p45381:::::::0.00: 0.00
MTSCHIAEEHIQKVAIFGGTHGNELTGVFLVKHWLENGAEIQRTGLEVKPFITNPRAVKK
CTRYIDCDLNRIFDLENLGKKMSEDLPYEVRRAQEINHLFGPKDSEDSYDIIFDLHNTTS
NMGCTLILEDSRNNFLIQMFHYIKTSLAPLPCYVYLIEHPSLKYATTRSIAKYPVGIEVG
PQPQGVLRADILDQMRKMIKHALDFIHHFNEGKEFPPCAIEVYKIIEKVDYPRDENGEIA
AIIHPNLQDQDWKPLHPGDPMFLTLDGKTIPLGGDCTVYPVFVNEAAYYEKKEAFAKTTK
LTLNAKSIRCCLH*

Alignment

Example alignment script for creating the pairwise alignment of 2GU2 and Aspa.

from modeller import *
env = environ()
# env.io.atom_files_directory = ["/apps/modeller9.9/bin/examples/commands/", "/path/to/your/files/"] ## o$
aln = alignment(env)
mdl = model(env, file='2GU2', model_segment=('FIRST:A', 'END:A'))
aln.append_model(mdl, align_codes='2GU2', atom_files='2GU2')
aln.append(file='../p45381.pir', align_codes='p45381')
aln.align2d()
aln.check()
aln.write(file='aspa_2gu2-2d.ali', alignment_format='PIR')
aln.malign()
aln.check()
aln.write(file='aspa_2gu2.ali', alignment_format='PIR')

Single template modelling

Example alignment script for creating a model of Aspartoacylase from a single template 2GU2:A.

from modeller import *
from modeller.automodel import *    
log.verbose()   
env = environ() 
# env.io.atom_files_directory = ["/apps/modeller9.9/bin/examples/commands/", "/path/to/your/files/"] ## only needed in the VirtualBox
a = automodel(env,
            alnfile  = 'aspa_2gu2-2d.ali',   
            knowns   = '2GU2A',              
            sequence = 'p45381',
            assess_methods=(assess.DOPE, assess.GA341))
a.starting_model= 1                
a.ending_model  = 1                
a.make()

Alignments for different templates

2GU2	<figure id="2gu2_align"></figure>
3NFZ	<figure id="3nfz_align"></figure>

I-Tasser

C-score is a confidence score for estimating the quality of predicted models by I-TASSER. It is calculated based on the significance of threading template alignments and the convergence parameters of the structure assembly simulations. C-score is typically in the range of [-5,2], where a C-score of higher value signifies a model with a high confidence and vice-versa.

Template > 80% Seq Id: 2GU2 (Rattus Norvegicus)

For the > 80% sequence identity template, we used default values, simply providing the template identifier 2GU2 and Chain A for modelling.