Abstract
By use of single internal radiolabels, 17 of the NH2-terminal 27 amino acids of the murine H-2Kb 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 str-ctural 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 beta2-mictoglobulin and immunoglobulins, but the available sequence information is insufficient for a satisfactory evaluation of its significance.