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UniProtKB/Swiss-Prot Q9UBP0: Variant p.Arg450Ser

Variant information

Variant position:  450
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 Arginine (R) to Serine (S) at position 450 (R450S, p.Arg450Ser).
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 large size and basic (R) to small size and polar (S)
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:  Spastic paraplegia 4, autosomal dominant (SPG4) [MIM:182601]: A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. {ECO:0000269|PubMed:10610178, ECO:0000269|PubMed:10699187, ECO:0000269|PubMed:11015453, ECO:0000269|PubMed:11039577, ECO:0000269|PubMed:11087788, ECO:0000269|PubMed:11309678, ECO:0000269|PubMed:11809724, ECO:0000269|PubMed:11843700, ECO:0000269|PubMed:11985387, ECO:0000269|PubMed:12124993, ECO:0000269|PubMed:12161613, ECO:0000269|PubMed:12163196, ECO:0000269|PubMed:12202986, ECO:0000269|PubMed:12460147, ECO:0000269|PubMed:12552568, ECO:0000269|PubMed:12939659, ECO:0000269|PubMed:14732620, ECO:0000269|PubMed:15159500, ECO:0000269|PubMed:15210521, ECO:0000269|PubMed:15248095, ECO:0000269|PubMed:15326248, ECO:0000269|PubMed:15482961, ECO:0000269|PubMed:15667412, ECO:0000269|PubMed:15716377, ECO:0000269|PubMed:15891913, ECO:0000269|PubMed:16339213, ECO:0000269|PubMed:16682546, ECO:0000269|PubMed:16684598, ECO:0000269|PubMed:17389232, ECO:0000269|PubMed:17594340, ECO:0000269|PubMed:19000169, ECO:0000269|PubMed:20214791, ECO:0000269|PubMed:20550563, ECO:0000269|PubMed:20562464, ECO:0000269|PubMed:20718791, ECO:0000269|PubMed:20932283, ECO:0000269|PubMed:21546041, ECO:0000269|PubMed:22960362, ECO:0000269|PubMed:23279441, ECO:0000269|PubMed:24824479, ECO:0000269|PubMed:25045380, ECO:0000269|PubMed:25421405, ECO:0000269|PubMed:28572275}. 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 SPG4.
Any additional useful information about the variant.

Sequence information

Variant position:  450
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  616
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 – 616 Spastin
Topological domain 78 – 616 Cytoplasmic
Region 228 – 616 Sufficient for microtubule severing
Mutagenesis 442 – 442 E -> Q. Abrogates ATP hydrolysis, abolishes microtubule severing, stabilizes the homohexameric form, and promotes microtubule binding and redistribution from the endosome to microtubules.
Mutagenesis 448 – 448 C -> AG. Abolishes ATPase activity.
Mutagenesis 448 – 448 C -> S. Does not affect ATPase activity.
Mutagenesis 451 – 451 R -> G. Abrogates binding to the tail of alpha-tubulin and beta-3-tubulin, impairs ATPase activity and abolishes microtubule severing.
Mutagenesis 457 – 457 A -> E. Abrogates binding to the tail of alpha-tubulin and beta-3-tubulin and abolishes microtubule severing.

Literature citations

Detection of novel mutations and review of published data suggests that hereditary spastic paraplegia caused by spastin (SPAST) mutations is found more often in males.
Proukakis C.; Moore D.; Labrum R.; Wood N.W.; Houlden H.;
J. Neurol. Sci. 306:62-65(2011)
Cited for: VARIANTS SPG4 MET-364; LEU-368; GLU-377 AND SER-450;

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.