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UniProtKB/Swiss-Prot variant pages

UniProtKB/Swiss-Prot Q16394: Variant p.Arg340Cys

Exostosin-1
Gene: EXT1
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Variant information Variant position: help 340 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Type of variant: help 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: help From Arginine (R) to Cysteine (C) at position 340 (R340C, p.Arg340Cys). 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: help Change from large size and basic (R) to medium size and polar (C) The physico-chemical property of the reference and variant residues and the change implicated.
BLOSUM score: help -3 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: help In EXT1; decreased glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity; decreased N-acetylglucosaminyl-proteoglycan 4-beta-glucuronosyltransferase activity; loss of heparan sulfate proteoglycan biosynthetic process; no effect on interaction with EXT2; can be integrated in heparan sulfate polymerase complex. Any additional useful information about the variant.
Other resources: help Links to websites of interest for the variant.


Sequence information Variant position: help 340 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Protein sequence length: help 746 The length of the canonical sequence.
Location on the sequence: help EKYDYREMLHNATFCLVPRG R RLGSFRFLEALQAACVPVML 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: help The multiple alignment of the region surrounding the variant against various orthologous sequences. 
Human                         EKYDYREMLHNATFCLVPRGRRLGSFRFLEALQAACVPVML

Mouse                         EKYDYREMLHNATFCLVPRGRRLGSFRFLEALQAACVPVML

Bovine                        EKYDYREMLHNATFCLVPRGRRLGSFRFLEALQAACVPVML

Caenorhabditis elegans        DRWEYDELLANSTFCLVPRGRRLGSFRFLETLRSGCVPVVI

Drosophila                    DRYDYETLLQNSTFCLVPRGRRLGSFRFLEALQAGCIPVLL
Sequence annotation in neighborhood: help 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 – 746 Exostosin-1
Topological domain 29 – 746 Lumenal
Binding site 324 – 324
Binding site 346 – 346
Binding site 349 – 349
Glycosylation 330 – 330 N-linked (GlcNAc...) asparagine
Disulfide bond 334 – 355
Mutagenesis 340 – 340 R -> A. Loss of N-acetylglucosaminyl-proteoglycan 4-beta-glucuronosyltransferase activity. No effect on glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity.
Mutagenesis 341 – 341 R -> A. Loss of N-acetylglucosaminyl-proteoglycan 4-beta-glucuronosyltransferase activity. No effect on glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity.
Mutagenesis 346 – 346 R -> A. Loss of N-acetylglucosaminyl-proteoglycan 4-beta-glucuronosyltransferase activity. No effect on glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity.
Beta strand 340 – 342



Literature citations
The putative tumour suppressor EXT1 alters the expression of cell-surface heparan sulfate.
McCormick C.; Leduc Y.; Martindale D.; Mattison K.; Esford L.E.; Dyer A.P.; Tufaro F.;
Nat. Genet. 19:158-161(1998)
Cited for: FUNCTION; PATHWAY; SUBCELLULAR LOCATION; GLYCOSYLATION; CHARACTERIZATION OF VARIANTS EXT1 ASP-339 AND CYS-340; The putative tumor suppressors EXT1 and EXT2 form a stable complex that accumulates in the Golgi apparatus and catalyzes the synthesis of heparan sulfate.
McCormick C.; Duncan G.; Goutsos K.T.; Tufaro F.;
Proc. Natl. Acad. Sci. U.S.A. 97:668-673(2000)
Cited for: FUNCTION; CATALYTIC ACTIVITY; PATHWAY; SUBUNIT; SUBCELLULAR LOCATION; CHARACTERIZATION OF VARIANTS EXT1 ASP-339 AND CYS-340; Association of EXT1 and EXT2, hereditary multiple exostoses gene products, in Golgi apparatus.
Kobayashi S.; Morimoto K.; Shimizu T.; Takahashi M.; Kurosawa H.; Shirasawa T.;
Biochem. Biophys. Res. Commun. 268:860-867(2000)
Cited for: SUBUNIT; SUBCELLULAR LOCATION; CHARACTERIZATION OF VARIANT EXT1 CYS-340; Mutation screening of the EXT1 and EXT2 genes in patients with hereditary multiple exostoses.
Philippe C.; Porter D.E.; Emerton M.E.; Wells D.E.; Simpson A.H.R.W.; Monaco A.P.;
Am. J. Hum. Genet. 61:520-528(1997)
Cited for: VARIANTS EXT1 ASP-339 AND CYS-340;
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.