Structure-based mutation analysis BCKDHA

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Revision as of 22:22, 29 June 2011 by Reisinger (talk | contribs) (foldX)

Structure selection

The following table presents the PDB structures for BCKDHA to date:

PDB id resolution [Å] R-factor coverage ph-value
1DTW 2.70 0.224 7.5*
1OLS 1.85 0.172 5.5
1OLU 1.90 0.161 5.5
1OLX 2.25 0.161 5.5
1U5B 1.83 0.156 5.8
1V11 1.95 0.139* 5.5
1V16 1.90 0.132* 5.5
1V1M 2.00 0.130* 5.5
1V1R 1.80 0.158 5.5
1WCI 1.84 0.149 5.5
1X7W 1.73 0.148 5.8
1X7X 2.10 0.149 5.8
1X7Y 1.57 0.150 5.8
1X7Z 1.72 0.154 5.8
1X80 2.00 0.161 5.8
2BEU 1.89 0.171 5.5
2BEV 1.80 0.139 5.5
2BEW 1.79 0.147 5.5
2BFB 1.77 0.145 5.5
2BFC 1.64 0.144 5.5
2BFD 1.39* 0.150 5.5
2BFE 1.69 0.150 5.5
2BFF 1.46 0.150 5.5
2J9F 1.88 0.171 5.5

The following PDB Structure was chosen because of its good experimental resolution: <bold></bold>

  • resultion:
  • R-factor
  • ph-value

Comparison energies

Mapping of the mutations on the crystal structure


Before we could use SCWRL we first had to get the sequence of our model: repairPDB bckdha.pdb -seq >> bckdha.seq

When we have the sequence we have to make one file for each mutation. In these files we copied the bckdha.seq and changed the sequence to lower case letters. Then we add the mutation in an upper case letter.

To run SCWRL we used the command: scwrl -i bckdha.pdb -s mutation1.seq -o mutation1Model.pdb

Total minimal energy of the graph

Position Energy
M82L 642.213
Q125E 616.85
Y166N 616.293
G249S 633.378
C264W 805.257
R265W 710.647
I326T 619.424
F409C 617.305
Y438N 615.951


To use foldX we first had to build a runscript. We create two different scripts one for the wildtype and one for the mutations.

Additionally we had to create one file with the PDB-ID (foldx_protein.txt). And for the mutation-script a file where the mutation is declared (mutant_file.txt).




<complex_with_DNA> true;

total energy difference
wildtype 402.35 0
mutant1 382.53 19.82
mutant2 331.79 71.56
mutant3 370.75 33.6
mutant4 394.97 10.38
mutant5 382.76 23.59
mutant6 324.92 82.43
mutant7 385.08 23.27
mutant8 394.32 15.03
mutant9 396.13 14.22



1. fetchpdb

The fetch-pdb script first checks, if it was called with an valid PDB-id. If the entered PDB code has 4letters, the script tries to download the pdb-file from the server. The successfully downloaded folder gets unzipped and everything except the actual pdb file is removed.

2. repairPDB



Warning: Starting residue K456 in chain not identified as Protein/RNA/DNA. Warning: Starting residue MN458 in chain not identified as Protein/RNA/DNA. Warning: Starting residue TDP556 in chain not identified as Protein/RNA/DNA.

und später dann: Fatal error: Residue 'MN' not found in residue topology database

removed first HAtoms: K, MN and TDP -> worked

5. MDP


grompp -v -f MDP_bckdha.mdp -c bckdha.gro -p -o bckdha.tpr

processing coordinates... double-checking input for internal consistency... Reading position restraint coords from bckdha.gro renumbering atomtypes...

GB parameter(s) missing or negative for atom type 'OW'

GB parameter(s) missing or negative for atom type 'HW'

Program grompp, VERSION 4.5.3 Source code file: /build/buildd/gromacs-4.5.3/src/kernel/grompp.c, line: 1123

Fatal error: Can't do GB electrostatics; the implicit_genborn_params section of the forcefield is missing parameters for 2 atomtypes or they might be negative. For more information and tips for troubleshooting, please check the GROMACS website at

7.System Minimization


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go to Reference Sequence BCKDHA