title: Complete sequence of HLA-B27 cDNA identified through the characterization of structural markers unique to the HLA-A, -B, and -C allelic series.
abstract: Antigen HLA-B27 is a high-risk genetic factor with respect to a group of rheumatoid disorders, especially ankylosing spondylitis. A cDNA library was constructed from an autozygous B-cell line expressing HLA-B27, HLA-Cw1, and the previously cloned HLA-A2 antigen. Clones detected with an HLA probe were isolated and sorted into homology groups by differential hybridization and restriction maps. Nucleotide sequencing allowed the unambiguous assignment of cDNAs to HLA-A, -B, and -C loci. The HLA-B27 mRNA has the structural features and the codon variability typical of an HLA class I transcript but it specifies two uncommon amino acid replacements: a cysteine in position 67 and a serine in position 131. The latter substitution may have functional consequences, because it occurs in a conserved region and at a position invariably occupied by a species-specific arginine in humans and lysine in mice. The availability of the complete sequence of HLA-B27 and of the partial sequence of HLA-Cw1 allows the recognition of locus-specific sequence markers, particularly, but not exclusively, in the transmembrane and cytoplasmic domains.
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000235:genetics; D006680:HLA Antigens / Q000235:genetics*; D015796:HLA-B27 Antigen; D015236:HLA-C Antigens; D006801:Humans; D008285:Major Histocompatibility Complex; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D006680:HLA Antigens; D015796:HLA-B27 Antigen; D015236:HLA-C Antigens; C047431:HLA-Cw1 antigen; D012333:RNA, Messenger; D004247:DNA