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UniProtKB/Swiss-Prot P02724: Variant p.Thr77Ile

Glycophorin-A
Gene: GYPA
Variant information

Variant position:  77
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  Polymorphism
The variants are classified into three categories: Disease, Polymorphism and Unclassified.
  • Disease: Variants implicated in disease according to literature reports.
  • Polymorphism: Variants not reported to be implicated in disease.
  • Unclassified: Variants with uncertain implication in disease according to literature reports. Evidence against or in favor of a pathogenic role is limited and/or conflicting.

Residue change:  From Threonine (T) to Isoleucine (I) at position 77 (T77I, p.Thr77Ile).
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 (T) to medium size and hydrophobic (I)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  -1
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:  Along with GYPB, GYPA is responsible for the MNS blood group system [MIM:111300]. The molecular basis of the GPA M/N bloodgroup antigen is a variation at positions 20 and 24. Ser-20 and Gly-24 correspond to M (shown); 'Leu-20' and 'Glu-24' correspond to N.GYPA polymorphisms are involved in resistance to malaria [MIM:611162]. -
Additional information on the polymorphism described.

Variant description:  In Mt(a) antigen.
Any additional useful information about the variant.

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



Sequence information

Variant position:  77
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  150
The length of the canonical sequence.

Location on the sequence:   PRAHEVSEISVRTVYPPEEE  T GERVQLAHHFSEPEITLIIF
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.

Human                         PRAHEVS-------EISVRTVYPPEEET-GERVQLAHHFSEPEITLIIF

                              PSTRQDP-------SGTMYQHLPDGGQK--ARQQLVHIFSE

Chimpanzee                    PRAHEVS-------EIYVTTVYPPEEEN-GEGVQLVHRFSE

Mouse                         PAIHVSTYHTAPTEVSAAFEEQPVSPHIGGMPSPIQHDFPA

Pig                           PSATSPG-------VMTIKNTTAVVQKETGVPESYHQDFSH

Horse                         PTFTTEQ-----------------DGREQGDGLQLAHDFSQ

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.

TypePositionsDescription
Chain 20 – 150 Glycophorin-A
Topological domain 20 – 91 Extracellular
Glycosylation 63 – 63 O-linked (GalNAc...) serine
Glycosylation 66 – 66 O-linked (GalNAc...) serine
Glycosylation 69 – 69 O-linked (GalNAc...) threonine
Mutagenesis 87 – 87 F -> C. Diminishes dimerization.
Mutagenesis 88 – 88 S -> C. Diminishes dimerization.
Mutagenesis 90 – 90 P -> C. Diminishes dimerization.
Mutagenesis 91 – 91 E -> C. Diminishes dimerization.
Mutagenesis 94 – 94 L -> I. Diminishes dimerization.
Mutagenesis 95 – 95 I -> A. Diminishes dimerization.


Literature citations

The MNS blood group antigens, Vr (MNS12) and Mt(a) (MNS14), each arise from an amino acid substitution on glycophorin A.
Storry J.R.; Coghlan G.; Poole J.; Figueroa D.; Reid M.E.;
Vox Sang. 78:52-56(2000)
Cited for: VARIANTS VR TYR-66 AND MT(A) ILE-77;

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.