Difference between revisions of "Sequence-based mutation analysis"

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(SNP's)
(SNP's)
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| C/Y,S || 282 || HGMD/dbSNP || -2/-1 || 3/11 || 3/7 || In both cases, the hydrophobicity is changed. Cysteine is a nonpolar whereas Serine and Tyrosine are polar amino acids.
 
| C/Y,S || 282 || HGMD/dbSNP || -2/-1 || 3/11 || 3/7 || In both cases, the hydrophobicity is changed. Cysteine is a nonpolar whereas Serine and Tyrosine are polar amino acids.
 
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| R/M || 330 || HGMD || -1 || 1 || 1 || The charge of the side chain changes from positive to neutral and the size is changing but this should not have such a strong impact like the different charge.
| R/M || 330 || HGMD || -1 || 1 || 1
 
 
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| A/V || 176 || HGMD || 0 || 13 || 9
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| A/V || 176 || HGMD || 0 || 13 || 9 || Alanin and Valine are pretty similar in there properties, just the size changes and the hydrophobicity decreases, but both are water soluble.
 
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| R/S || 6 || HGMD || -1 || 11 || 6
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| R/S || 6 || HGMD || -1 || 11 || 6 || The polarity is changing which has an impact on the surface on the water solubility of the protein.
 
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| T/I || 217 || dbSNP || -1 || 7 || 4
 
| T/I || 217 || dbSNP || -1 || 7 || 4
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| M/T || 35 || dbSNP || -1 || 6 || 5
 
| M/T || 35 || dbSNP || -1 || 6 || 5
 
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| R/M || 58 || dbSNP || -1 || 1 || 1 || The charge of the side chain changes from positive to neutral and the size is changing but this should not have such a strong impact like the different charge.
| R/M || 58 || dbSNP || -1 || 1 || 1
 
 
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Revision as of 14:08, 26 June 2011

SNP's

Because the HFE-Gen has no annotated functional site, we can just adress the biochemical changes for each SNP. A change in functionality or stability can not described.
To compare the biochemical properties of the amino acid's, we used the very convenient function of wolfram alpha and the Wikipedia entry about amino acids <ref>http://en.wikipedia.org/wiki/Amino_acid</ref>.

Mutation Position Database Blosum62 PAM1 Pam250 Physicochemical changes
S/C 65 HGMD/dbSNP -1 5 3 There is no change in size and charge, just the polarity changes because an oxigen atom is replaced by a sulfur atom.
I/T 105 HGMD/dbSNP -1 11 6 An OH-group is replaced by an ethyl-group which leads so a small change in size and a large change in hydrophobicity.
Q/H 127 HGMD/dbSNP 0 20 7 Because of the aromatic ring, the flexibility is reduced with a histidine at this position. The polarity and hydrophobicity remain the same.
C/Y,S 282 HGMD/dbSNP -2/-1 3/11 3/7 In both cases, the hydrophobicity is changed. Cysteine is a nonpolar whereas Serine and Tyrosine are polar amino acids.
R/M 330 HGMD -1 1 1 The charge of the side chain changes from positive to neutral and the size is changing but this should not have such a strong impact like the different charge.
A/V 176 HGMD 0 13 9 Alanin and Valine are pretty similar in there properties, just the size changes and the hydrophobicity decreases, but both are water soluble.
R/S 6 HGMD -1 11 6 The polarity is changing which has an impact on the surface on the water solubility of the protein.
T/I 217 dbSNP -1 7 4
M/T 35 dbSNP -1 6 5
R/M 58 dbSNP -1 1 1 The charge of the side chain changes from positive to neutral and the size is changing but this should not have such a strong impact like the different charge.

A change in polarity is just important for residues at the surface of the protein, because with a change in polarity, the hydrophobicity changes and so the water solubility decreases/increases.

SIFT

The prediction of SIFT is marked with a low confidence warning because, the sequences used for the prediction were not diverse enough.

Mutation Position Prediction Score Cause disease
S/C 65 AFFECT PROTEIN FUNCTION 0.00 yes
I/T 105 AFFECT PROTEIN FUNCTION 0.00 yes
Q/H 127 TOLERATED 0.16 yes
C/Y,S 282 AFFECT PROTEIN FUNCTION 0.00 yes
R/M 330 TOLERATED 0.06 yes
A/V 176 AFFECT PROTEIN FUNCTION 0.01 yes
R/S 6 AFFECT PROTEIN FUNCTION 0.01 yes
T/I 217 TOLERATED 1.00
M/T 35 TOLERATED 1.00
R/M 58 AFFECT PROTEIN FUNCTION 0.00

The complete prediction for each position and amino acid can be found here

We got three warning messages form SIFT for which we have no explanation at this time.

WARNING: Original amino acid H at position 31 is not allowed by the prediction. 
WARNING: Original amino acid S at position 45 is not allowed by the prediction. 
WARNING: Original amino acid Y at position 230 is not allowed by the prediction.

PolyPhen-2

Mutation Position Prediction Score Cause disease
S/C 65 PROBABLY DAMAGING 0.997 yes
I/T 105 PROBABLY DAMAGING 0.998 yes
Q/H 127 BENIGN 0.002 yes
C/Y,S 282 PROBABLY DAMAGING 1.000/0.997 yes
R/M 330 PROBABLY DAMAGING 0.948 yes
A/V 176 PROBABLY DAMAGING 0.998 yes
R/S 6 PROBABLY DAMAGING 0.738 yes
T/I 217 BENIGN 0.195
M/T 35 PROBABLY DAMAGING 0.989
R/M 58 PROBABLY DAMAGING 0.998

References

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