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UniProtKB/Swiss-Prot P17405: Variant p.Cys159Arg

Sphingomyelin phosphodiesterase
Gene: SMPD1
Variant information

Variant position:  159
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 Cysteine (C) to Arginine (R) at position 159 (C159R, p.Cys159Arg).
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 polar (C) to large size and basic (R)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  -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:  In NPDB.
Any additional useful information about the variant.

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

Sequence information

Variant position:  159
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  631
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 47 – 631 Sphingomyelin phosphodiesterase
Domain 87 – 171 Saposin B-type
Glycosylation 177 – 177 N-linked (GlcNAc...) asparagine
Disulfide bond 91 – 167
Disulfide bond 94 – 159
Mutagenesis 151 – 151 S -> A. No effect on sphingomyelin phosphodiesterase activity. No effect on subcellular location. No effect on phosphorylation by PRKCD.
Mutagenesis 177 – 177 N -> G. Reduces protein levels. Reduces sphingomyelin phosphodiesterase activity. No effect on secretion.
Helix 155 – 163

Literature citations

Cloning of a human acid sphingomyelinase cDNA with a new mutation that renders the enzyme inactive.
Ida H.; Rennert O.M.; Eto Y.; Chan W.Y.;
J. Biochem. 114:15-20(1993)

The demographics and distribution of type B Niemann-Pick disease: novel mutations lead to new genotype/phenotype correlations.
Simonaro C.M.; Desnick R.J.; McGovern M.M.; Wasserstein M.P.; Schuchman E.H.;
Am. J. Hum. Genet. 71:1413-1419(2002)
Cited for: VARIANTS NPDB VAL-51; TRP-94; PRO-139; ARG-159; PRO-198; CYS-202; MET-227; CYS-230; ASP-234; SER-247; ARG-250; HIS-291; ALA-325; ARG-332; ASP-359; HIS-378; LEU-378; PRO-381; VAL-415; TYR-423; ARG-433; PRO-434; CYS-437; VAL-454; ASP-458; TRP-476; LEU-477; LEU-482; ASN-490; SER-496; CYS-498; GLN-516; VAL-517; ARG-535; PRO-551; ASN-578; HIS-602 AND PRO-602; VARIANT VAL-487;

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.