Zajonc Dirk M, Elsliger Marc A, Teyton Luc, Wilson Ian A
Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Nat Immunol. 2003 Aug;4(8):808-15. doi: 10.1038/ni948. Epub 2003 Jun 29.
CD1 antigens bind a variety of self and foreign lipid and glycolipid antigens for presentation to CD1-restricted T cell receptors (TCRs). Here we report the crystal structure of human CD1a in complex with a sulfatide self antigen at a resolution of 2.15 A. The lipid adopts an S-shaped conformation, with the sphingosine chain completely buried in the A' pocket and the fatty acid chain emerging from the interface of the A' pocket into the more exposed F' pocket. The headgroup is anchored in the A'-F' junction and protrudes into the F' pocket for TCR recognition. Because the A' pocket is narrow with a fixed terminus, it can act as a molecular 'ruler' to select alkyl chains of a particular length.
CD1抗原结合多种自身及外来脂质和糖脂抗原，以呈递给受CD1限制的T细胞受体（TCR）。在此，我们报告了人CD1a与硫酸脑苷脂自身抗原复合物的晶体结构，分辨率为2.15埃。脂质呈S形构象，鞘氨醇链完全埋于A'口袋中，脂肪酸链从A'口袋的界面伸出进入更暴露的F'口袋。头部基团锚定在A'-F'交界处，并伸入F'口袋以供TCR识别。由于A'口袋狭窄且有固定末端，它可作为分子“尺子”来选择特定长度的烷基链。
