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Figure 1.
Fig. 1. A representation of the mCD1d-iGb3 complex (a) and
chemical structures of CD1d ligands (b). a, The self-antigen
iGb3 (yellow) is bound in the hydrophobic binding groove between
the α1 and α2 helices of the CD1d heavy chain (grey) that
associates non-covalently with β[2]-microblobulin (β[2]M,
blue-grey) to form a biological heterodimer. Three of the four
N-linked glycosylation sites (Asn20 (N20), Asn42 and Asn165)
carry well-ordered carbohydrates (grey sticks). The spacer lipid
(C[16], orange) present in the binding groove complements the
short C[8]-alkyl chain of the synthetic ligand iGb3. b, The
chemical structure of short-chain iGb3 is different from that of
cis-tetracosenoyl sulfatide (sulfatide C[24:1]), which it
resembles in the core structure, and the short-chain α-GalCer,
which is dissimilar due to the different anomeric conformation
of the galactose (α-versus β-glycosidic linkage). The terminal
α1-3 linked galactose (red) is not ordered in the crystal
structure and, therefore, not shown in Fig. 1 and Fig. 2).
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