TY - JOUR
T1 - Structures of the Erythrina corallodendron lectin and of its complexes with mono- and disaccharides
AU - Elgavish, Sharona
AU - Shaanan, Boaz
PY - 1998/4/10
Y1 - 1998/4/10
N2 - The structures of the Erythrina corallodendron lectin (EcorL) and of its complexes with galactose, N-acetylgalactosamine, lactose and N-acetyllactosamine were determined at a resolution of 1.9 to 1.95 Å. The final R-values of the five models are in the range 0.169 to 0.181. The unusual, non-canonical, dimer interface of EcorL is made of β-strands from the two monomers, which face one another in a 'hand-shake' mode. The galactose molecule in the primary binding site is bound in an identical way in all four complexes. Features of the electrostatic potential of the galactose molecule match those of the potential in the combining site, thus probably pointing to the contribution of the electrostatic energy to determining the orientation of the ligand. No conformational change occurs in the protein upon binding the ligand. Subtle variations in the binding mode of the second monosaccharide (glucose in the complex with lactose and N-acetylglucosamine in the complex with N-acetyllactosamine) were observed. The mobility of Gln219 is lower in the complexes with the disaccharides than in the complexes with the monosaccharides, indicating further recruitment of this residue to ligand binding through more extensive hydrogen bonding in the former complexes. Water molecules that have been located in the combining sites of the five structures undergo rearrangement in response to binding of the different ligands. The new structural information is in qualitative agreement with thermodynamic data on the binding to EcorL.
AB - The structures of the Erythrina corallodendron lectin (EcorL) and of its complexes with galactose, N-acetylgalactosamine, lactose and N-acetyllactosamine were determined at a resolution of 1.9 to 1.95 Å. The final R-values of the five models are in the range 0.169 to 0.181. The unusual, non-canonical, dimer interface of EcorL is made of β-strands from the two monomers, which face one another in a 'hand-shake' mode. The galactose molecule in the primary binding site is bound in an identical way in all four complexes. Features of the electrostatic potential of the galactose molecule match those of the potential in the combining site, thus probably pointing to the contribution of the electrostatic energy to determining the orientation of the ligand. No conformational change occurs in the protein upon binding the ligand. Subtle variations in the binding mode of the second monosaccharide (glucose in the complex with lactose and N-acetylglucosamine in the complex with N-acetyllactosamine) were observed. The mobility of Gln219 is lower in the complexes with the disaccharides than in the complexes with the monosaccharides, indicating further recruitment of this residue to ligand binding through more extensive hydrogen bonding in the former complexes. Water molecules that have been located in the combining sites of the five structures undergo rearrangement in response to binding of the different ligands. The new structural information is in qualitative agreement with thermodynamic data on the binding to EcorL.
KW - Carbohydrate specificity
KW - Lectins
KW - Protein-carbohydrate interactions
UR - http://www.scopus.com/inward/record.url?scp=0032502896&partnerID=8YFLogxK
U2 - 10.1006/jmbi.1998.1664
DO - 10.1006/jmbi.1998.1664
M3 - Article
C2 - 9545381
AN - SCOPUS:0032502896
SN - 0022-2836
VL - 277
SP - 917
EP - 932
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 4
ER -