1GIC

CONCANAVALIN A COMPLEXED WITH METHYL ALPHA-D-GLUCOPYRANOSIDE

Summary for 1GIC

• Entry DOI: 10.2210/pdb1gic/pdb
• Descriptor: CONCANAVALIN A, methyl alpha-D-glucopyranoside, MANGANESE (II) ION, ... (5 entities in total)
• Functional Keywords: complex, lectin, saccharide
• Biological source: Canavalia ensiformis (jack bean)
• Total number of polymer chains: 2
• Total formula weight: 51823.17

Authors

Bradbrook, G.M.,Gleichmann, T.,Harrop, S.J.,Helliwell, J.R.,Habash, J.,Kalb(Gilboa), A.J.,Tong, L.,Wan, T.C.M.,Yariv, J. (deposition date: 1996-08-08, release date: 1997-08-20, Last modification date: 2024-05-22)

Primary citation

Harrop, S.J.,Helliwell, J.R.,Wan, T.C.,Kalb, A.J.,Tong, L.,Yariv, J.
Structure solution of a cubic crystal of concanavalin A complexed with methyl alpha-D-glucopyranoside.
Acta Crystallogr.,Sect.D, 52:143-155, 1996

PubMed Abstract: The solution of the cubic crystal form (a = 167.8 A) of concanavalin A complexed with the monosaccharide methyl alpha-D-glucopyranoside is described. The space group has been determined as I2(1)3 rather than I23. The use of cadmium to replace cobalt at the transition metal-ion binding site and to replace calcium at its binding site proved to be crucial to the successful solution of the crystal structure. The relatively small isomorphous signals of 21 e(-) for the replacement of cobalt and 28 e(-) for the replacement of calcium, yielded interpretable difference Patterson maps. The electron-density map calculated in space group I2(1)3 at 5.4 A resolution, based on phases derived from single- and double-substituted cadmium differences, revealed a classical concanavalin A tetramer of 222 point symmetry, as seen in all the known crystal structures of concanavalin A. Rigid-body refinement at 3.6 A using the refined coordinates of saccharide-free concanavalin A converged to an R factor of 27.4%. A molecular-replacement analysis, consistent with this crystal structure, and initial experiences in the incorrect space group I23 are described as these also prove to be instructive.

PubMed: 15299735
DOI: 10.1107/S0907444995008742

Experimental method

X-RAY DIFFRACTION (2 Å)