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UniProtKB/Swiss-Prot P00966: Variant p.Val263Met

Argininosuccinate synthase
Gene: ASS1
Variant information

Variant position:  263
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  LP/P [Disclaimer]
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 Valine (V) to Methionine (M) at position 263 (V263M, p.Val263Met).
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:  Similar physico-chemical property. Both residues are medium size and hydrophobic.
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:  In CTLN1; mild clinical course; no effect on affinity for aspartate; no effect on affinity for citrulline; decreased argininosuccinate synthase activity.
Any additional useful information about the variant.

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



Sequence information

Variant position:  263
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  412
The length of the canonical sequence.

Location on the sequence:   THQTSLELFMYLNEVAGKHG  V GRIDIVENRFIGMKSRGIYE
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                         TH----QTSLELFMYLNEVAGKHGVGRIDIVENRFIGMKSRGIYE

Mouse                         TR----TTSLELFMYLNEVAGKHGVGRIDIVENRFIGMKSR

Rat                           TH----STSLDLFMYLNEVAGKHGVGRIDIVENRFIGMKSR

Bovine                        TH----STALELFLYLNEVAGKHGVGRIDIVENRFIGMKSR

Chicken                       TH----RSALELFVYLNDIASKHGVGRVDIVENRFVGMKSR

Xenopus laevis                QH----SSSLALFCYLNEVAGKHGVGRIDIVENRFIGMKSR

Xenopus tropicalis            QH----SSALGLFCYLNEVAGKHGVGRIDIVENRFIGMKSR

Zebrafish                     SK----ETPLEIFCYLNEIGGKHGVGRIDIVENRFIGMKSR

Drosophila                    VY----TKPLEMLDFLNKLGGSYGIGRIDIVENRFVGLKSR

Baker's yeast                 SKEVSVTKPLDVFLAASNLARANGVGRIDIVEDRYINLKSR

Fission yeast                 F-----SGVVSIFYQLNAIARRNGVGRIDIVENRFSGLKSR

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 – 412 Argininosuccinate synthase
Binding site 270 – 270 Citrulline
Binding site 282 – 282 Citrulline


Literature citations

Mild citrullinemia in Caucasians is an allelic variant of argininosuccinate synthetase deficiency (citrullinemia type 1).
Haeberle J.; Pauli S.; Schmidt E.; Schulze-Eilfing B.; Berning C.; Koch H.G.;
Mol. Genet. Metab. 80:302-306(2003)
Cited for: VARIANTS CTLN1 SER-14; LEU-40; GLN-127; ARG-179; ASP-190; GLU-202; MET-263; MET-269; SER-324; GLY-345 AND VAL-362;

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.