Expasy logo

UniProtKB/Swiss-Prot variant pages

UniProtKB/Swiss-Prot P08397: Variant p.Arg201Trp

Porphobilinogen deaminase
Gene: HMBS
Feedback?
Variant information Variant position: help 201 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 Tryptophan (W) at position 201 (R201W, p.Arg201Trp). 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 large size and aromatic (W) 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 AIP; residual activity. Any additional useful information about the variant.
Other resources: help Links to websites of interest for the variant.


Sequence information Variant position: help 201 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Protein sequence length: help 361 The length of the canonical sequence.
Location on the sequence: help QEFSAIILATAGLQRMGWHN R VGQILHPEECMYAVGQGALG 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                         QEFSAIILATAGLQRMGWHNRVGQILHPEECMYAVGQGALG

Mouse                         QEFSAIVLAVAGLQRMGWQNRVGQILHPEECMYAVGQGALA

Rat                           LEFSAIILAVAGLQRMGWQNRVGQILHPEECMYAVGQGALA

Bovine                        QEFSAIILATAGLQRMGWQNRVGQILHPEECMYAVGQGALG

Slime mold                    NGYDGMILAVAGLERMELTDHISEIIPDSISLYAVGQGSLG

Baker's yeast                 SPYQCIILASAGLMRMGLENRITQRFHSDTMYHAVGQGALG

Fission yeast                 SQFDCLVLAAAGLFRLGLKDRIAQMLTAPFVYYAVGQGALA
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 2 – 361 Porphobilinogen deaminase
Mutagenesis 195 – 195 R -> A. Loss of hydroxymethylbilane synthase activity.
Helix 199 – 201



Literature citations
Two new mutations in the porphobilinogen deaminase gene and a screening method using PCR amplification of specific alleles.
Lundin G.; Wedell A.; Thunell S.; Anvret M.;
Hum. Genet. 93:59-62(1994)
Cited for: VARIANT AIP TRP-201; Acute intermittent porphyria: identification and expression of exonic mutations in the hydroxymethylbilane synthase gene. An initiation codon missense mutation in the housekeeping transcript causes 'variant acute intermittent porphyria' with normal expression of the erythroid-specific enzyme.
Chen C.-H.; Astrin K.H.; Lee G.; Anderson K.E.; Desnick R.J.;
J. Clin. Invest. 94:1927-1937(1994)
Cited for: VARIANTS AIP PHE-93; TRP-116; TRP-201 AND PHE-247; Genetic investigation of the porphobilinogen deaminase gene in Swedish acute intermittent porphyria families.
Lundin G.; Lee J.-S.; Thunell S.; Anvret M.;
Hum. Genet. 100:63-66(1997)
Cited for: VARIANTS AIP TRP-116; LEU-119; GLN-167; TRP-167; TRP-173; TRP-201 AND ASP-216; Identification and characterization of hydroxymethylbilane synthase mutations causing acute intermittent porphyria: evidence for an ancestral founder of the common G111R mutation.
De Siervi A.; Rossetti M.V.; Parera V.E.; Astrin K.H.; Aizencang G.I.; Glass I.A.; Batlle A.M.C.; Desnick R.J.;
Am. J. Med. Genet. 86:366-375(1999)
Cited for: VARIANTS AIP PRO-34; ARG-111; TRP-173; TRP-201; 329-LEU--GLN-332 DEL AND SER-335;
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.