these analyses it became clear that the MHC class I molecule com prised a distinct groove on the external side of the molecule. The sides of the groove are formed by the a-helical structures of the a and a 1 2 domains and a floor which is formed by 8 anti-parallel 13 strands. The various polymorphic residues, as determined from DNA sequence analysis, are localized within these a-helices and 13-plated sheets within the groove. More importantly, these analyses also revealed the presence of elec tron-dense material in the groove. This material was subsequently iden 568 10 tified as a linear...
these analyses it became clear that the MHC class I molecule com prised a distinct groove on the external side of the molecule. The sides of the groov...
