UniProtKB/Swiss-Prot Q03393: Variant p.Leu26Phe

6-pyruvoyl tetrahydrobiopterin synthase
Gene: PTS
Chromosomal location: 11q22.3-q23.3
Variant information

Variant position:  26
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 have been found in patients and disease-association is reported in literature. However, this classification is not a definitive assessment of variant pathogenicity.
  • Polymorphism: No disease-association has been reported.
  • Unclassified: Variants have been found in patients but disease-association remains unclear.

Residue change:  From Leucine (L) to Phenylalanine (F) at position 26 (L26F, p.Leu26Phe).
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 hydrophobic (L) to large size and aromatic (F)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  0
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:  Hyperphenylalaninemia, BH4-deficient, A (HPABH4A) [MIM:261640]: An autosomal recessive disorder characterized by hyperphenylalaninemia, depletion of the neurotransmitters dopamine and serotonin, and progressive cognitive and motor deficits. Neurological symptoms are unresponsive to the classic phenylalanine-low diet. {ECO:0000269|PubMed:10220141, ECO:0000269|PubMed:10585341, ECO:0000269|PubMed:10874306, ECO:0000269|PubMed:11388593, ECO:0000269|PubMed:7698774, ECO:0000269|PubMed:8178819, ECO:0000269|PubMed:8707300, ECO:0000269|PubMed:9159737, ECO:0000269|PubMed:9222757, ECO:0000269|PubMed:9450907}. 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 HPABH4A.
Any additional useful information about the variant.

Sequence information

Variant position:  26
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  145
The length of the canonical sequence.

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.







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.

Chain 1 – 145 6-pyruvoyl tetrahydrobiopterin synthase
Active site 43 – 43 Proton acceptor
Metal binding 24 – 24 Zinc
Modified residue 19 – 19 Phosphoserine; by PKG
Modified residue 28 – 28 Phosphoserine
Mutagenesis 19 – 19 S -> A. Decrease in activity; abolishes phosphorylation by PKG.

Literature citations

Molecular analysis and long-term follow-up of patients with different forms of 6-pyruvoyl-tetrahydropterin synthase deficiency.
Dudesek A.; Roeschinger W.; Muntau A.C.; Seidel J.; Leupold D.; Thoeny B.; Blau N.;
Eur. J. Pediatr. 160:267-276(2001)
Cited for: VARIANTS HPABH4A PHE-26; MET-67; LEU-87; LEU-124; GLY-136 AND VAL-136;

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.