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UniProtKB/Swiss-Prot variant pages

UniProtKB/Swiss-Prot P05177: Variant p.Arg456His

Cytochrome P450 1A2
Gene: CYP1A2
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Variant information Variant position: help 456 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Type of variant: help LB/B 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 Histidine (H) at position 456 (R456H, p.Arg456His). 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 (H) The physico-chemical property of the reference and variant residues and the change implicated.
BLOSUM score: help 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

Polymorphism: help The CYP1A2*1F allele which is quite common (40 to 50%) is due to a substitution of a base in the non-coding region of the CYP1A2 gene and has the effect of decreasing the enzyme inducibility. Individuals who are homozygous for the CYP1A2*1F allele are 'slow' caffeine metabolizers. Thus for these individual increased intake of caffeine seems to be associated with a concomitant increase in the risk of non-fatal myocardial infraction (MI). Additional information on the polymorphism described.
Variant description: help In allele CYP1A2*8. Any additional useful information about the variant.
Other resources: help Links to websites of interest for the variant.


Sequence information Variant position: help 456 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Protein sequence length: help 516 The length of the canonical sequence.
Location on the sequence: help DGTAINKPLSEKMMLFGMGK R RCIGEVLAKWEIFLFLAILL 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                         DGTAINKPLSEKMMLFGMGKRRCIGEVLAKWEIFLFLAILL

                              DGTTINKTLSEKVMLFGMGKRRCIGEVLAKWEIFLFLAILL

Mouse                         NNSAIDKTQSEKVMLFGLGKRRCIGEIPAKWEVFLFLAILL

Rat                           DNTAIDKTLSEKVMLFGLGKRRCIGEIPAKWEVFLFLAILL

Rabbit                        DGAAINKPLSEKVTLFGLGKRRCIGETLARWEVFLFLAILL

Cat                           DGTAINKILSEKVMIFGLGKRRCIGEVLAKWEVFLFLAILL

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 – 516 Cytochrome P450 1A2
Binding site 458 – 458 axial binding residue
Helix 454 – 456



Literature citations
Single nucleotide polymorphisms and haplotypes of CYP1A2 in a Japanese population.
Soyama A.; Saito Y.; Hanioka N.; Maekawa K.; Komamura K.; Kamakura S.; Kitakaze M.; Tomoike H.; Ueno K.; Goto Y.; Kimura H.; Katoh M.; Sugai K.; Saitoh O.; Kawai M.; Ohnuma T.; Ohtsuki T.; Suzuki C.; Minami N.; Kamatani N.; Ozawa S.; Sawada J.;
Drug Metab. Pharmacokinet. 20:24-33(2005)
Cited for: VARIANTS ARG-42; GLN-377 AND HIS-456;
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.