title: Molecular definition of an elusive third HLA-A9 molecule: HLA-A9.3.
abstract: The HLA-A9 family has been characterized as possessing two well defined specificities; HLA-A23 and A24. Serological studies have suggested the presence of a third member of this family HLA-A9.3, however there is doubt surrounding the existence of this specificity. HLA-A23, A24, and the putative A9.3 proteins were analyzed biochemically by immunoprecipitation and isoelectric focusing. Both HLA-A24 and A9.3 have identical isoelectric points whereas A23 is different. We have sequenced cDNA encoding HLA-A23, A24, and A9.3. From the observed protein sequences, we found A9.3 to differ from A24 by two amino acid substitutions located in the alpha 2 helix of the class I molecule. These substitutions are expected to significantly change the shape of the peptide binding cleft.
authors.affiliation: Department of Cell Biology, Stanford University School of Medicine, CA 94305-5400.
authors.forename: A M
authors.initials: AM
authors.lastname: Little
authors.forename: J A
authors.initials: JA
authors.lastname: Madrigal
authors.forename: P
authors.initials: P
authors.lastname: Parham
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D015234:HLA-A Antigens / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction
chemical_list: D015234:HLA-A Antigens; C037709:HLA-A9 antigen; D009838:Oligodeoxyribonucleotides