Abstract
We have isolated and determined the sequence of a genomic clone containing the gene for a human class I transplantation antigen. The gene contains seven exons. The first five exons code respectively for a signal peptide, for the first, second, and third extracellular domains of the protein molecule, and for the transmembrane region. The cytoplasmic segment is encoded by part of the fifth and the sixth and the seventh exons. The structure of the protein encoded by this unit is closely homologous with known class I transplantation antigens.