2d7f | pdb_00002d7f
Crystal structure of A lectin from canavalia gladiata seeds complexed with alpha-methyl-mannoside and alpha-aminobutyric acid
Structural highlights
Function[CONA_CANGL] Glucose/D-mannose/rhamnose specific lectin. Has hemagglutinating activity towards rabbit erythrocytes. Has mitogenic activity towards murine splenocytes that is inhibited by glucose. Inhibits HIV-1 reverse transcriptase with an IC(50) of 35uM. Has a potent antiproliferative activity against L1210 leukemia cells in vitro that is not inhibited by glucose. Inhibits translation in cell-free rabbit reticulocyte system with an IC(50) of 2.08uM. Lacks anti-fungal activity against M.arachidicola, B.cenera and F.oxysporum.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: Lectins are mainly described as simple carbohydrate-binding proteins. Previous studies have tried to identify other binding sites, which possible recognize plant hormones, secondary metabolites, and isolated amino acid residues. We report the crystal structure of a lectin isolated from Canavalia gladiata seeds (CGL), describing a new binding pocket, which may be related to pathogen resistance activity in ConA-like lectins; a site where a non-protein amino-acid, alpha-aminobutyric acid (Abu), is bound. RESULTS: The overall structure of native CGL and complexed with alpha-methyl-mannoside and Abu have been refined at 2.3 A and 2.31 A resolution, respectively. Analysis of the electron density maps of the CGL structure shows clearly the presence of Abu, which was confirmed by mass spectrometry. CONCLUSION: The presence of Abu in a plant lectin structure strongly indicates the ability of lectins on carrying secondary metabolites. Comparison of the amino acids composing the site with other legume lectins revealed that this site is conserved, providing an evidence of the biological relevance of this site. This new action of lectins strengthens their role in defense mechanisms in plants. Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules.,Delatorre P, Rocha BA, Souza EP, Oliveira TM, Bezerra GA, Moreno FB, Freitas BT, Santi-Gadelha T, Sampaio AH, Azevedo WF Jr, Cavada BS BMC Struct Biol. 2007 Aug 2;7:52. PMID:17683532[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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