Homology-based structure prediction (PKU)

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Revision as of 16:32, 29 May 2012 by Hollizeck (talk | contribs) (PDBe)

Short Task Description

After the sequence based predictions of function and secondary structure for our protein we will determine the 3D structure of the wild type protein and observe the influence one or several SNPs have on this structure. Of the variety of methods to be used for tertiary structure prediction, we choose homology modeling as a first approach to our goal. Read the complete task description here. The protocol of commands and scripts can be found in our journal

Model Construction

Here we will show the steps we took building the models we then use and evaluate. In order to start the sheer model-building we first have to construct some datasets, which will be the founding of our models.

Datasets

These datasets were derived from serveral sources. They all consist of PDB-entries, but we ensured to no include the already known structure of our protein, so we have a better insight in the topic of homology modeling with a completely unknown sequence.

PDBe

<figtable id="tab:datasetpdbe"> Dataset PDBe

pdb ID E-value Identity in %
> 80% sequence identity
2phm 4.1e-148 95.5
40% - 80% sequence identity
2xsn 6e-100 61.1
1toh 1e-99 60.8
3e2t 8.5e-99 64.4
1mlw 1.1e-95 66.1
3hf8 1.5e-92 66.4
< 30% sequence identity
3l0i 6.7 25
3uan 18 24.8
1vkj 20 24.8
3hv0 71 21.7
</figtable>

For this set of datasets we used the webservice of sequence similarity search provieded by the pdb called PDBeXplore, which can be accessed here. In the used dataset (see <xr id="tab:datasetpdbe" /> we restricted the received data from pdb, such as we didnt use the structure of both the monomer and the dimer etc. We also did not use the structure with different ligands in order to keep the variability high.

HHPred

Coma

Modelevaluation