Figure 3
From: The structure of SeviL, a GM1b/asialo-GM1 binding R-type lectin from the mussel Mytilisepta virgata
(A) The structure of the related glycosphingolipids GM1, GM1b and asialo-GM1. The glucose is linked in each case to ceramide. (B) A stereo view of the least-squares overlay of the tetrasaccharide bound to SeviL and the GM1 saccharide found in models from PDB of different lectin complexes. Each saccharide was overlaid by least-squares fit of ten atoms of the Gal-2 residue (omitting O1 and O6). Carbon atoms of asialo-GM1 bound to SeviL are shown in white. Carbon atoms of other complexes are shown with the colours green (endoglycoceramidase I, PDB 5j7z)35, orange (polyomavirus genotype 3 VP1, PDB 4x0z)36, purple (polyomavirus VP1, PDB 4u60)37, dark green (ECX AB5 holotoxin, PDB 4l6t)38, pink (Agrocybe aegerita lectin AAL, PDB 3m3q)39, yellow (cholera toxin B-pentamer, PDB 3chb)40. (C) A stereo view showing the saccharide of GM1 modelled into the binding site of SeviL by overlay of the Gal-2 residue. The sialic acid residue of GM1 clashes strongly with Phe 32 of the protein.
