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UniProtKB/Swiss-Prot O43525: Variant p.Asp305Gly

Potassium voltage-gated channel subfamily KQT member 3
Gene: KCNQ3
Chromosomal location: 8q24
Variant information

Variant position:  305
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  Disease [Disclaimer]
The variants are classified into three categories: Disease, Polymorphism and Unclassified.
  • Disease: Variants implicated in disease according to literature reports.
  • Polymorphism: Variants not reported to be implicated in disease.
  • Unclassified: Variants with uncertain implication in disease according to literature reports. Evidence against or in favor of a pathogenic role is limited and/or conflicting.

Residue change:  From Aspartate (D) to Glycine (G) at position 305 (D305G, p.Asp305Gly).
Indicates the amino acid change of the variant. The one-letter and three-letter codes for amino acids used in UniProtKB/Swiss-Prot are those adopted by the commission on Biochemical Nomenclature of the IUPAC-IUB.

Physico-chemical properties:  Change from medium size and acidic (D) to glycine (G)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  -1
The score within a Blosum matrix for the corresponding wild-type to variant amino acid change. The log-odds score measures the logarithm for the ratio of the likelihood of two amino acids appearing by chance. The Blosum62 substitution matrix is used. This substitution matrix contains scores for all possible exchanges of one amino acid with another:
  • Lowest score: -4 (low probability of substitution).
  • Highest score: 11 (high probability of substitution).
More information can be found on the following page

Involvement in disease:  Seizures, benign familial neonatal 2 (BFNS2) [MIM:121201]: A disorder characterized by clusters of seizures occurring in the first days of life. Most patients have spontaneous remission by 12 months of age and show normal psychomotor development. The disorder is distinguished from benign familial infantile seizures by an earlier age at onset. {ECO:0000269|PubMed:10852552, ECO:0000269|PubMed:14534157, ECO:0000269|PubMed:25982755, ECO:0000269|PubMed:9425900, ECO:0000269|PubMed:9872318}. Note=The disease is caused by mutations affecting the gene represented in this entry.
The name and a short description of the disease associated with the variant. For more information about the disease, the user can refer to OMIM, following the link provided after the disease acronym.

Variant description:  In BFNS2; reduces the maximal heteromeric current by 40% with no alteration in voltage dependence of activation or deactivation kinetics.
Any additional useful information about the variant.

Other resources:  
Links to websites of interest for the variant.



Sequence information

Variant position:  305
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  872
The length of the canonical sequence.

Location on the sequence:   DVPEVDAQGEEMKEEFETYA  D ALWWGLITLATIGYGDKTPK
The residue change on the sequence. Unless the variant is located at the beginning or at the end of the protein sequence, both residues upstream (20) and downstream (20) of the variant will be shown.

Residue conservation: 
The multiple alignment of the region surrounding the variant against various orthologous sequences.

Human                         DVPEVDAQGEEMKEEFETYADALWWGLITLATIGYGDKTPK

Mouse                         DVPEMDAQGEEMKEEFETYADALWWGLITLATIGYGDKTPK

Rat                           DVPEMDAQGEEMKEEFETYADALWWGLITLATIGYGDKTPK

Bovine                        DVPEVDAQGEEMKEEFETYADALWWGLITLATIGYGDKTPK

Sequence annotation in neighborhood:  
The regions or sites of interest surrounding the variant. In general the features listed are posttranslational modifications, binding sites, enzyme active sites, local secondary structure or other characteristics reported in the cited references. The "Sequence annotation in neighborhood" lines have a fixed format:
  • Type: the type of sequence feature.
  • Positions: endpoints of the sequence feature.
  • Description: contains additional information about the feature.

TypePositionsDescription
Chain 1 – 872 Potassium voltage-gated channel subfamily KQT member 3
Intramembrane 304 – 324 Pore-forming; Name=Segment H5
Mutagenesis 318 – 318 G -> S. >50% Reduction of wt heteromeric current; ratio of 1:1 and 1:1:2.


Literature citations

KCNQ2 and KCNQ3 potassium channel genes in benign familial neonatal convulsions: expansion of the functional and mutation spectrum.
Singh N.A.; Westenskow P.; Charlier C.; Pappas C.; Leslie J.; Dillon J.; Anderson V.E.; Sanguinetti M.C.; Leppert M.F.;
Brain 126:2726-2737(2003)
Cited for: VARIANTS BFNS2 GLY-305 AND VAL-310; CHARACTERIZATION OF VARIANT BFNS2 GLY-305; VARIANT SER-468; CHARACTERIZATION OF VARIANT SER-468; FUNCTION;

Disclaimer: Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. They are not in any way intended to be used as a substitute for professional medical advice, diagnostic, treatment or care.