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UniProtKB/Swiss-Prot Q12791: Variant p.Glu656Ala

Calcium-activated potassium channel subunit alpha-1
Gene: KCNMA1
Variant information

Variant position:  656
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  US
The variants are classified into three categories: LP/P, LB/B and US.
  • LP/P: likely pathogenic or pathogenic.
  • LB/B: likely benign or benign.
  • US: uncertain significance

Residue change:  From Glutamate (E) to Alanine (A) at position 656 (E656A, p.Glu656Ala).
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 (E) to small size and hydrophobic (A)
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

Variant description:  Found in a patient with epilepsy; unknown pathological significance; no effect on voltage-dependent sensitivity.
Any additional useful information about the variant.

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



Sequence information

Variant position:  656
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  1236
The length of the canonical sequence.

Location on the sequence:   KSANRESRILINPGNHLKIQ  E GTLGFFIASDAKEVKRAFFY
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                         KSANRESR----ILINPGNHLKIQEGTLGFFIASDAKEVKRAFFY

Mouse                         KSANRESRSRKRILINPGNHLKIQEGTLGFFIASDAKEVKR

Rat                           KSANRESRSRKRILINPGNHLKIQEGTLGFFIASDAKEVKR

Bovine                        KSANRESR----ILINPGNHLKIQEGTLGFFIASDAKEVKR

Rabbit                        KSANRESR----ILINPGNHLKIQEGTLGFFIASDAKEVKR

Chicken                       KSEKRESS----ILINPGNHVKIQEGTLGFFIASDAKEVKR

Xenopus laevis                KSEKGESR----ILINPGNHMKIKEGTLGFFIASDAKEVKR

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 – 1236 Calcium-activated potassium channel subunit alpha-1
Topological domain 389 – 1236 Cytoplasmic
Alternative sequence 169 – 1236 Missing. In isoform 6.
Alternative sequence 643 – 643 R -> RSRKR. In isoform 3.


Literature citations

De novo BK channel variant causes epilepsy by affecting voltage gating but not Ca2+ sensitivity.
Li X.; Poschmann S.; Chen Q.; Fazeli W.; Oundjian N.J.; Snoeijen-Schouwenaars F.M.; Fricke O.; Kamsteeg E.J.; Willemsen M.; Wang Q.K.;
Eur. J. Hum. Genet. 26:220-229(2018)
Cited for: FUNCTION; INVOLVEMENT IN EIG16; VARIANT EIG16 SER-1053; CHARACTERIZATION OF VARIANT EIG16 SER-1053; VARIANTS ASN-518; ALA-656 AND SER-1217; CHARACTERIZATION OF VARIANTS ASN-518; ALA-656 AND SER-1217;

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.