X-ray crystal structure of the human galectin-3 carbohydrate recognition domain at 2.1-A resolution.
Galectins are a family of lectins which share similar carbohydrate recognition domains (CRDs) and affinity for small beta-galactosides, but which show significant differences in binding specificity for more complex glycoconjugates. We report here the x-ray crystal structure of the human galectin-3 CRD, in complex with lactose and N-acetyllactosamine, at 2.1-A resolution. This structure represents the first example of a CRD determined from a galectin which does not show the canonical 2-fold symmetric dimer organization. Comparison with the published structures of galectins-1 and -2 provides an explanation for the differences in carbohydrate-binding specificity shown by galectin-3, and for the fact that it fails to form dimers by analogous CRD-CRD interactions.
Seetharaman
J
J
Departments of Molecular and Medical Genetics and Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
Kanigsberg
A
A
Slaaby
R
R
Leffler
H
H
Barondes
S H
SH
Rini
J M
JM
D000818:Animals; D000943:Antigens, Differentiation / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D018360:Crystallography, X-Ray; D019281:Dimerization; D037483:Galectin 1; D037501:Galectin 2; D037502:Galectin 3; D006388:Hemagglutinins / Q000737:chemistry; D006801:Humans; D008958:Models, Molecular
D000943:Antigens, Differentiation; D037483:Galectin 1; D037501:Galectin 2; D037502:Galectin 3; D006388:Hemagglutinins