Structural studies on protein products of murine chromosome 17: Partial amino acid sequence of an H-2K(b) molecule

By use of single internal radiolabels, 17 of the NH₂ terminal 27 amino acids of the murine H2 Kb molecule have been assigned. When the amino acid sequence is compared to that of the murine H 2Kk molecule, there is a minimum of six amino acid differences in 19 positions. This high degree of structural diversity confirms, at the level of amino acid sequence, the known polymorphism of the murine H 2 complex. Significant primary structural homology is evident when the murine H 2Kk and H 2Kb sequences are compared to the recently reported partial amino acid sequences of human transplantation antigens. There is modest homology with β₂ microglobulin and immunoglobulins, but the available sequence information is insufficient for a satisfactory evaluation of its significance.