3NBC

Clitocybe nebularis ricin B-like lectin (CNL) in complex with lactose, crystallized at pH 4.4

Summary for 3NBC

• Entry DOI: 10.2210/pdb3nbc/pdb
• Related: 3NBD 3NBE
• Related PRD ID: PRD_900004
• Descriptor: Ricin B-like lectin, beta-D-galactopyranose-(1-4)-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: clitocybe nebularis ricin b-like lectin, lactose, sugar binding protein
• Biological source: Clitocybe nebularis
• Total number of polymer chains: 2
• Total formula weight: 32083.38

Authors

Renko, M.,Pohleven, J.,Sabotic, J.,Kos, J.,Turk, D. (deposition date: 2010-06-03, release date: 2011-09-21, Last modification date: 2024-04-03)

Primary citation

Pohleven, J.,Renko, M.,Magister, S.,Smith, D.F.,Kunzler, M.,Strukelj, B.,Turk, D.,Kos, J.,Sabotic, J.
Bivalent carbohydrate binding is required for biological activity of Clitocybe nebularis lectin (CNL), the N,N'-diacetyllactosediamine (GalNAc beta 1-4GlcNAc, LacdiNAc)-specific lectin from basidiomycete C. nebularis
J.Biol.Chem., 287:10602-10612, 2012

PubMed Abstract: Lectins are carbohydrate-binding proteins that exert their biological activity by binding to specific cell glycoreceptors. We have expressed CNL, a ricin B-like lectin from the basidiomycete Clitocybe nebularis in Escherichia coli. The recombinant lectin, rCNL, agglutinates human blood group A erythrocytes and is specific for the unique glycan N,N'-diacetyllactosediamine (GalNAcβ1-4GlcNAc, LacdiNAc) as demonstrated by glycan microarray analysis. We here describe the crystal structures of rCNL in complex with lactose and LacdiNAc, defining its interactions with the sugars. CNL is a homodimeric lectin, each of whose monomers consist of a single ricin B lectin domain with its β-trefoil fold and one carbohydrate-binding site. To study the mode of CNL action, a nonsugar-binding mutant and nondimerizing monovalent CNL mutants that retain carbohydrate-binding activity were prepared. rCNL and the mutants were examined for their biological activities against Jurkat human leukemic T cells and the hypersensitive nematode Caenorhabditis elegans mutant strain pmk-1. rCNL was toxic against both, although the mutants were inactive. Thus, the bivalent carbohydrate-binding property of homodimeric CNL is essential for its activity, providing one of the rare pieces of evidence that certain activities of lectins are associated with their multivalency.

PubMed: 22298779
DOI: 10.1074/jbc.M111.317263

Experimental method

X-RAY DIFFRACTION (1.01 Å)