Batuwangala Thil, Shepherd Dawn, Gadola Stephan D, Gibson Kevin J C, Zaccai Nathan R, Fersht Alan R, Besra Gurdyal S, Cerundolo Vincenzo, Jones E Yvonne
Cancer Research UK Receptor Structure Group, The Division of Structural Biology, and Cancer Research UK.
J Immunol. 2004 Feb 15;172(4):2382-8. doi: 10.4049/jimmunol.172.4.2382.
The human MHC class I-like molecule CD1b is distinctive among CD1 alleles in that it is capable of presenting a set of glycolipid species that show a very broad range of variation in the lengths of their acyl chains. A structure of CD1b complexed with relatively short acyl chain glycolipids plus detergent suggested how an interlinked network of channels within the Ag-binding groove could accommodate acyl chain lengths of up to 80 carbons. The structure of CD1b complexed with glucose monomycolate, reported in this study, confirms this hypothesis and illustrates how the distinctive substituents of intracellular bacterial glycolipids can be accommodated. The Ag-binding groove of CD1b is, uniquely among CD1 alleles, partitioned into channels suitable for the compact accommodation of lengthy acyl chains. The current crystal structure illustrates for the first time the binding of a natural bacterial lipid Ag to CD1b and shows how its novel structural features fit this molecule for its role in the immune response to intracellular bacteria.
人类MHC I类样分子CD1b在CD1等位基因中独具特色，因为它能够呈递一组糖脂种类，这些糖脂的酰基链长度变化范围非常广泛。CD1b与相对短的酰基链糖脂以及去污剂形成的复合物结构表明，抗原结合槽内相互连接的通道网络如何能够容纳长达80个碳原子的酰基链长度。本研究报道的CD1b与单霉菌酸葡萄糖形成的复合物结构证实了这一假设，并说明了细胞内细菌糖脂的独特取代基是如何被容纳的。CD1b的抗原结合槽在CD1等位基因中独一无二，被分隔成适合紧密容纳长酰基链的通道。当前的晶体结构首次展示了天然细菌脂质抗原与CD1b的结合，并显示了其新颖的结构特征如何使该分子适合其在针对细胞内细菌的免疫反应中的作用。
