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UniProtKB/Swiss-Prot variant pages

UniProtKB/Swiss-Prot P33261: Variant p.Arg433Trp

Cytochrome P450 2C19
Gene: CYP2C19
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Variant information Variant position: help 433
Type of variant: help LB/B
Residue change: help From Arginine (R) to Tryptophan (W) at position 433 (R433W, p.Arg433Trp).
Physico-chemical properties: help Change from large size and basic (R) to large size and aromatic (W)
BLOSUM score: help -3
Polymorphism: help Genetic variation in CYP2C19 is responsible for poor drug metabolism [MIM:609535]. Individuals can be characterized as either extensive metabolizers (EM) or poor metabolizers (PM). The PM phenotype is inherited in an autosomal recessive manner, with the EM phenotype comprising both homozygous dominant and heterozygote genotypes. There are marked interracial differences in the frequency of this polymorphism. Poor metabolizers represent 2-5% of Caucasians, 13-23% of Asian populations, and as many as 38-79% of individuals of some of the islands of Polynesia and Micronesia. At least 38 different alleles are known including CYP2C19*1A, CYP2C19*1B, CYP2C19*1C, CYP2C19*2A (CYP2C19m1 or CYP2C19m1A), CYP2C19*2B (CYP2C19m1B), CYP2C19*2C (CYP2C19*21), CYP2C19*3A (CYP2C19m2), CYP2C19*3B (CYP2C19*20), CYP2C19*4 (CYP2C19m3), CYP2C19*5A (CYP2C19m4), CYP2C19*5B, CYP2C19*6, CYP2C19*7, CYP2C19*8, CYP2C19*9, CYP2C19*10, CYP2C19*11 CYP2C19*12, CYP2C19*13, CYP2C19*14 CYP2C19*15, CYP2C19*16, CYP2C19*18 and CYP2C19*19. Defective CYP2C19*2 and CYP2C19*3 alleles are characterized by a splice mutation and a stop codon, respectively, and account for most of the PM alleles. The sequence shown is that of allele CYP2C19*1A.
Variant description: help In allele CYP2C19*5A and allele CYP2C19*5B; loss of activity.
Other resources: help


Sequence information Variant position: help 433
Protein sequence length: help 490
Location on the sequence: help LDEGGNFKKSNYFMPFSAGK R ICVGEGLARMELFLFLTFIL
Sequence annotation in neighborhood: help
TypePositionsDescription
Chain 1 – 490 Cytochrome P450 2C19
Binding site 435 – 435 axial binding residue



Literature citations
Differences in the incidence of the CYP2C19 polymorphism affecting the S-mephenytoin phenotype in Chinese Han and Bai populations and identification of a new rare CYP2C19 mutant allele.
Xiao Z.S.; Goldstein J.A.; Xie H.G.; Blaisdell J.; Wang W.; Jiang C.H.; Yan F.X.; He N.; Huang S.L.; Xu Z.H.; Zhou H.H.;
J. Pharmacol. Exp. Ther. 281:604-609(1997)
Cited for: VARIANT TRP-433; An additional defective allele, CYP2C19*5, contributes to the S-mephenytoin poor metabolizer phenotype in Caucasians.
Ibeanu G.C.; Blaisdell J.; Ghanayem B.I.; Beyeler C.; Benhamou S.; Bouchardy C.; Wilkinson G.R.; Dayer P.; Daly A.K.; Goldstein J.A.;
Pharmacogenetics 8:129-135(1998)
Cited for: VARIANT TRP-433;
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.