Lab journal task 4

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Revision as of 12:27, 12 August 2013 by Betza (talk | contribs)

First, we used Pymol to view the different structures and to construct structural alignments to the template 1A6Z_A. Therfore we used the command " align to structure" from the action menu.

The pymol alignment uses only the C_alpha atoms per default. The following command can be used to align all atoms and create the object ali12

align structure1 and resi 1-n, structure2 and resi 1-m, object=ali12 

,where n equals the number of atoms in structure 1 and m the number of atoms in structure 2.

We saved the current view of the first alignment

my_view = cmd.get_view()

and then used this variable later to set the orientation to these values, in order to be able to make images from the different alignments always using the same view.

cmd.set_view(my_view)

<css> table.colBasic2 { margin-left: auto; margin-right: auto; border: 2px solid black; border-collapse:collapse; width: 70%; }

.colBasic2 th,td { padding: 3px; border: 2px solid black; }

.colBasic2 td { text-align:left; }

.colBasic2 tr th { background-color:#efefef; color: black;} .colBasic2 tr:first-child th { background-color:#adceff; color:black;} </css>

Apart from Pymol, the following four alignment methods were used:

LGA:
  • superimpose to target structure (second structure, in our case 1A6Z )
  • default parameters
SSAP:
  • no target structure to specify
  • no parameters to set
  • score from 0 to 100
TopMatch:
  • target 1A6Z
  • default parameters
  • target in blue, query in green
  • structurally equivalent residue pairs: orange (query) and red (target)
  • S = Measure of structural similarity based on Gaussian functions (see Sippl & Wiederstein (2012)). If the structurally equivalent parts in query and target match perfectly, S is equal to L. With increasing spatial deviation of the aligned residues, S approaches 0.
  • S_r = Typical distance error. For details on the construction of this per-residue measure of structural similarity, see Sippl & Wiederstein (2012).
method name location
LGA http://proteinmodel.org/AS2TS/LGA/lga.html
SSAP http://protein.hbu.cn/cath/cathwww.biochem.ucl.ac.uk/cgi-bin/cath/GetSsapRasmol.html
TopMatch https://topmatch.services.came.sbg.ac.at/
CE http://source.rcsb.org/jfatcatserver/index.jsp