Allelic repertoire of the human MHC class I MICA gene.
The hallmark of the classical major histocompatibility complex (MHC) class I molecules is their astonishing level of polymorphism, a characteristic not shared by the nonclassical MHC class I genes. A distinct family of MHC class I genes has been recently identified within the human MHC class I region. The MICA (MHC class I chain-related A) gene in this family is a highly divergent member of the MHC class I family and has a unique pattern of tissue expression. We have sequenced exons encoding the extracellular alpha1, alpha2, and alpha3 domains of the MICA gene from twenty HLA homozygous typing cell lines and four unrelated individuals. We report the identification of eleven new alleles defined by a total of twenty-two amino acid substitutions. Thus, the total number of MICA alleles is sixteen. Interestingly, a tentative superimposition of MICA variable residues on the HLA-A2 structure reveals a unique pattern of distribution, concentrated primarily on the outer edge of the MICA putative antigen binding cleft, apparently bordering an invariant ligand binding site.
Fodil
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N
Centre de Recherche d'Immunologie et d'Hématologie, 4 rue Kirschleger, 67085 Strasbourg Cedex, France.
Laloux
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L
Wanner
V
V
Pellet
P
P
Hauptmann
G
G
Mizuki
N
N
Inoko
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H
Spies
T
T
Theodorou
I
I
Bahram
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S
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D005805:Genes, MHC Class I; D015789:HLA-A2 Antigen / Q000737:chemistry; D015395:Histocompatibility Antigens Class I / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D015789:HLA-A2 Antigen; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A