Crystal structure of Pterocarpus angolensis lectin in complex with glucose, sucrose, and turanose.
The crystal structure of the Man/Glc-specific seed lectin from Pterocarpus angolensis was determined in complex with methyl-alpha-d-glucose, sucrose, and turanose. The carbohydrate binding site contains a classic Man/Glc type specificity loop. Its metal binding loop on the other hand is of the long type, different from what is observed in other Man/Glc-specific legume lectins. Glucose binding in the primary binding site is reminiscent of the glucose complexes of concanavalin A and lentil lectin. Sucrose is found to be bound in a conformation similar as seen in the binding site of lentil lectin. A direct hydrogen bond between Ser-137(OG) to Fru(O2) in Pterocarpus angolensis lectin replaces a water-mediated interaction in the equivalent complex of lentil lectin. In the turanose complex, the binding site of the first molecule in the asymmetric unit contains the alphaGlc1-3betaFruf form of furanose while the second molecule contains the alphaGlc1-3betaFrup form in its binding site.
Loris
Remy
R
Laboratorium voor Ultrastructuur, Instituut voor Moleculaire Biologie, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium. reloris@vub.ac.be
Imberty
Anne
A
Beeckmans
Sonia
S
Van Driessche
Edilbert
E
Read
John S
JS
Bouckaert
Julie
J
De Greve
Henri
H
Buts
Lieven
L
Wyns
Lode
L
D001665:Binding Sites; D003460:Crystallization; D004187:Disaccharides / Q000737:chemistry* / Q000378:metabolism; D005947:Glucose / Q000737:chemistry* / Q000378:metabolism; D008968:Molecular Conformation; D037121:Plant Lectins / Q000737:chemistry* / Q000378:metabolism; D035721:Pterocarpus / Q000737:chemistry*; D013395:Sucrose / Q000737:chemistry* / Q000378:metabolism
D004187:Disaccharides; D037121:Plant Lectins; D013395:Sucrose; C029454:turanose; D005947:Glucose