Amino acid sequence of the cytoplasmic segment of the h-2Kd (H2.31) murine major histocompatibility antigen.

The primary structure of the carboxy-terminal portion of the H-2Kd murine major histocompatibility antigen has been determined using radiosequencing methodology. The two peptides encompassing the entire cytoplasmic portion of the H-2Kd molecule were isolated from cyanogen bromide digests of the detergent solubilized molecule. These two peptides are not present in CNBr digests of papain-solubilized H-2Kd. Alignment of the two CNBr peptides was deduced from tryptic overlap peptides derived from the whole molecule. Alignment with the corresponding region of the H-2Kb antigen shows 90% homology and supports the assignment of this segment of H-2Kd as the C-terminal. The sequence obtained in this study is (Met)-Arg-Arg-Asn-Thr-Gly-Gly-Lys-Gly-Val-Asn-Tyr-Ala-Leu-Ala-Pro-Gly-Ser-Gln- Thr-Ser-Asp-Leu-Ser-Leu-Pro-Asp-Pro-Lys-Val-Met-Val-His-Asp-Pro-His-Ser-Leu- Ala. These data allow extensive comparisons with the protein sequences deduced from the 3' ends of H-2d haplotype cDNA and genomic clones as well as with the homologous regions of H-2Kb and H-2Db.