Determination of the HLA-DM interaction site on HLA-DR molecules
Determination of the HLA-DM interaction site on HLA-DR molecules
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DOI：
10.1016/s1074-7613(00)00051-0
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发表时间：
2000-10-01
期刊：
影响因子：
32.4
通讯作者：
Mellins, ED
中科院分区：
文献类型：
--
作者：
Doebele, RC;Busch, R;Mellins, ED
HLA-DM从MHC II类分子中去除CLIP和其他松散结合的肽。II类分子和HLA-DM的晶体结构不允许识别它们的相互作用位点。在这里，我们描述了损害与DM相互作用的II类突变。筛选随机诱变的DR 3 α和β链的文库，以确定其在EBV-B细胞中引起CLIP/DR 3复合物细胞表面积累的能力。如SDS稳定性测定所检测，七种突变与体内肽负载受损相关。在体外，这些突变DR 3分子对DM催化的CLIP释放具有抗性，并显示与DM的结合减少。所有突变定位于HLA-DR的一个侧面，我们建议在肽交换过程中与DM相互作用。
HLA-DM removes CLIP and other loosely bound peptides from MHC class II molecules. The crystal structures of class II molecules and of HLA-DM have not permitted identification of their interaction sites. Here, we describe mutations in class II that impair interactions with DM. Libraries of randomly mutagenized DR3 alpha and beta chains were screened for their ability to cause cell surface accumulation of CLIP/DR3 complexes in EBV-B cells. Seven mutations were associated with impaired peptide loading in vivo, as detected by SDS stability assays. In vitro, these mutant DR3 molecules were resistant to DM-catalyzed CLIP release and showed reduced binding to DM. All mutations localize to a single lateral face of HLA-DR, which we propose interacts with DM during peptide exchange.