cDNA clone coding for part of a mouse H-2d major histocompatibility antigen.

mRNA coding for mouse major transplantation antigens of the d haplotype was partially purified, copied into double-stranded cDNA, and cloned in Escherichia coli. Clones were selected by their ability to hybridize specifically with mRNA coding for H-2K, D, or L antigens. One of these clones, pH-2d-1, carries a 1200-base-pair insert, comprising the noncoding region, including poly(A) at the 3' end and part of the coding region. A partial sequence of the latter region showed extensive homology with the known amino acid sequences of H-2Kb,Kk, and HLA-B7 antigens. From this comparison, it appears that the coding region extends from amino acid 133 in the second domain, through the third domain, to the cytoplasmic COOH-terminal region. A stretch of 24 hydrophobic or uncharged residues, located 31 amino acids from the COOH-terminal end, could represent the segment that spans the membrane. This is followed on the cytoplasmic side of the membrane by a cluster of basic amino acids and a possible phosphorylation site on a threonine residue.