1B2P: Native Mannose-Specific Bulb Lectin From Scilla Campanulata (Bluebell) At 1.7 Angstroms Resolution

The X-ray crystal structure of native Scilla campanulata agglutinin, a mannose-specific lectin from bluebell bulbs and a member of the Liliaceae family, has been determined by molecular replacement and refined to an R value of 0.186 at 1.7 A resolution. The lectin crystallizes in space group P21212 with unit-cell parameters a = 70. 42, b = 92.95, c = 46.64 A. The unit cell contains eight protein molecules of Mr = 13143 Da (119 amino-acid residues). The asymmetric unit comprises two chemically identical molecules, A and B, related by a non-crystallographic twofold axis perpendicular to c. This dimer further associates by crystallographic twofold symmetry to form a tetramer. The fold of the polypeptide backbone closely resembles that found in the lectins from Galanthus nivalis (snowdrop) and Hippeastrum (amaryllis) and contains a threefold symmetric beta-prism made up of three antiparallel four-stranded beta-sheets. Each of the four-stranded beta-sheets (I, II and III) possesses a potential saccharide-binding site containing conserved residues; however, site II has two mutations relative to sites I and III which may prevent ligation at this site. Our study provides the first accurate and detailed description of a native (unligated) structure from this superfamily of mannose-specific bulb lectins and will allow comparisons with a number of lectin-saccharide complexes which have already been determined or are currently under investigation.
PDB ID: 1B2PDownload
MMDB ID: 10709
PDB Deposition Date: 1998/11/30
Updated in MMDB: 2007/11
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 1B2P: tetrameric; determined by author and by software (PQS)
Molecular Components in 1B2P
Label Count Molecule
Proteins (4 molecules)
Protein (Lectin)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB