O'Callaghan C A, Tormo J, Willcox B E, Braud V M, Jakobsen B K, Stuart D I, McMichael A J, Bell J I, Jones E Y
Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, United Kingdom.
Mol Cell. 1998 Mar;1(4):531-41. doi: 10.1016/s1097-2765(00)80053-2.
The crystal structure of the nonclassical human class lb MHC molecule HLA-E has been determined in complex with a prototypic ligand, the nonamer peptide (VMAPRTVLL), derived from the highly conserved residues 3-11 of the human MHC class la leader sequence. The mode of peptide binding retains some of the standard features observed in MHC class la complexes, but novel features imply that HLA-E has evolved to mediate specific binding to a tightly defined set of almost identical hydrophobic peptides from the highly conserved class l leader sequences. These molecular adaptations make HLA-E a rigorous checkpoint at the cell surface reporting on the integrity of the antigen processing pathway to CD94/NKG2 receptor-bearing natural killer cells.
非经典人类I类b型主要组织相容性复合体（MHC）分子HLA - E的晶体结构已被确定，它与一种原型配体——九聚体肽（VMAPRTVLL）形成复合物，该肽源自人类MHC I类a型前导序列高度保守的3 - 11位残基。肽结合模式保留了一些在MHC I类a型复合物中观察到的标准特征，但新特征表明HLA - E已经进化到可介导与来自高度保守的I类前导序列的一组紧密定义的几乎相同的疏水肽进行特异性结合。这些分子适应性使HLA - E成为细胞表面的一个严格检查点，向携带CD94/NKG2受体的自然杀伤细胞报告抗原加工途径的完整性。
