Structural basis of oligomannose recognition by the Pterocarpus angolensis seed lectin.

TitleStructural basis of oligomannose recognition by the Pterocarpus angolensis seed lectin.
Publication TypeJournal Article
Year of Publication2004
AuthorsLoris, R., I. Van Walle, H. De Greve, S. Beeckmans, F. Deboeck, L. Wyns, and J. Bouckaert
JournalJ Mol Biol
Date Published2004 Jan 30
KeywordsAmino Acid Sequence, Binding Sites, Concanavalin A, Crystallization, Maackia, Mannose, Models, Molecular, Molecular Conformation, Molecular Sequence Data, Oligosaccharides, Plant Lectins, Pterocarpus, Seeds, Sequence Homology, Amino Acid

The crystal structure of a Man/Glc-specific lectin from the seeds of the bloodwood tree (Pterocarpus angolensis), a leguminous plant from central Africa, has been determined in complex with mannose and five manno-oligosaccharides. The lectin contains a classical mannose-specificity loop, but its metal-binding loop resembles that of lectins of unrelated specificity from Ulex europaeus and Maackia amurensis. As a consequence, the interactions with mannose in the primary binding site are conserved, but details of carbohydrate-binding outside the primary binding site differ from those seen in the equivalent carbohydrate complexes of concanavalin A. These observations explain the differences in their respective fine specificity profiles for oligomannoses. While Man(alpha1-3)Man and Man(alpha1-3)[Man(alpha1-6)]Man bind to PAL in low-energy conformations identical with that of ConA, Man(alpha1-6)Man is required to adopt a different conformation. Man(alpha1-2)Man can bind only in a single binding mode, in sharp contrast to ConA, which creates a higher affinity for this disaccharide by allowing two binding modes.

Alternate JournalJ. Mol. Biol.
PubMed ID14729339