Difference between revisions of "Homology-modelling HEXA"

From Bioinformatikpedia
Line 170: Line 170:
| [[Image:wrong_res_3cui.png|thumb|Prediction of the wrong predicted residues]]
| [[Image:wrong_res_3cui.png|thumb|Prediction of the wrong predicted residues]]
Model qualitity:
Model qualitity:

Revision as of 14:26, 12 June 2011

Homology structure groups

We decided to choose every 5% one protein:

> 60% sequence identity
PDB id name similarity single template
1ht6_A AMY1, alpha-amylase iso 95%
3aj7_A Oligo-1,6-glucosidase 90%
1h4p_A Glucan 1,3-beta-glucosidase 85.2%
3bc9_A AMYB, alpha amylase, ca 80.8% X
2zum_A 458AA long hypothetical 75%
3bmv_A Cyclomaltodextrin gluca 70.3%
2f2h_A Putative family 31 gluc 64.8%
3emz_A Xylanase, endo-1,4-beta 61%
> 40%
2dep_A Xylanase B, thermostabl 54.9%
3cui_A EXO-beta-1,4-glucanase; 49.5% X
1vhc_A Putative KHG/KDPG aldol 45.1%
2hk0_A D-psicose 3-epimerase 40.8%
< 40%
2g0w_A LMO2234 protein; putati 35.5%
3q94_A Fructose-bisphosphate a 30.0%
3hn3_A Beta-G1, beta-glucuroni 25.1%
3lut_A Voltage-gated potassium 20.1% X

Calculation of the models


To calculate the models with Swiss-Model we used the [Webserver]. For the template with high sequence identity, we used the automated and the alignment method, for the other two templates we only used the alignment method.

The used alignments can be found [here].


We used Modeller from the command line. Therefore we followed the instructions, described [here].

First of all, we created an alignment for each of our three selected sequences. In the next step we used Modeller to model the 3D structure of the protein.

For Modeller we used the Pir Alignment format, which can be found here: [3BC9], [3CUI], [3LUT]


To calculate our models with iTasser we used the [Webserver]. We defined the target and template sequence, but this time without an alignment. We used the same template sequences as before.






The detailed prediction can be found [here]

Swiss-Model also give same scores to give the user the possibility to estimate the quality of the predicted model, which are showed in the next paragraphes.

The most important score in the following table is the QMEAN4 score, because this score consists of the scores above and give the user the possibility to compare different results.

 Global Score
Scoring function term Raw score Z score
C_beta interaction energy 202.24 -4.65
All-atom pairwise energy 9942.28 -6.16
Solvation energy 67.79 -8.08
Torsion angle energy 76.36 -7.72
QMEAN4 score 0.057 -11.76

Swiss-Modeler also returns some pictures, which show the qualitity of the model.

Predicted Structure:

Prediction the structure of HEXA_HUMAN with 3cui as template structure
Prediction of the wrong predicted residues

Model qualitity:

Visualisation of the QMEAN Z-Score for this model
Visualisation of the QMEAN score in comparison with a gaussian distribution
Quality of the model in comparison to a X-ray structure
Plot, which shows the wrong predicted residues of this model