Cloning and characterization of a monocot mannose-binding lectin from Crocus vernus (family Iridaceae)
| Autor: | E J, Van Damme, C H, Astoul, A, Barre, P, Rougé, W J, Peumans |
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| Rok vydání: | 2000 |
| Předmět: |
Models
Molecular Sequence Homology Amino Acid Macromolecular Substances Molecular Sequence Data Protein Structure Secondary Recombinant Proteins Evolution Molecular Magnoliopsida Mannose-Binding Lectins Carbohydrate Sequence Agglutinins Lectins Carbohydrate Conformation Amino Acid Sequence Cloning Molecular Plant Lectins Mannose Sequence Alignment Phylogeny |
| Zdroj: | European journal of biochemistry. 267(16) |
| ISSN: | 0014-2956 |
| Popis: | The molecular structure and carbohydrate-binding activity of the lectin from bulbs of spring crocus (Crocus vernus) has been determined unambiguously using a combination of protein analysis and cDNA cloning. Molecular cloning revealed that the lectin called C. vernus agglutinin (CVA) is encoded by a precursor consisting of two tandemly arrayed lectin domains with a reasonable sequence similarity to the monocot mannose-binding lectins. Post-translational cleavage of the precursor yields two equally sized polypeptides. Mature CVA consists of two pairs of polypeptides and hence is a heterotetrameric protein. Surface plasmon resonance studies of the interaction of the crocus lectin with high mannose-type glycans showed that the lectin interacts specifically with exposed alpha-1,3-dimannosyl motifs. Molecular modelling studies confirmed further the close relationships in overall fold and three-dimensional structure of the mannose-binding sites of the crocus lectin and other monocot mannose-binding lectins. However, docking experiments indicate that only one of the six putative mannose-binding sites of the CVA protomer is active. These results can explain the weak carbohydrate-binding activity and low specific agglutination activity of the lectin. As the cloning and characterization of the spring crocus lectin demonstrate that the monocot mannose-binding lectins occur also within the family Iridaceae a refined model of the molecular evolution of this lectin family is proposed. |
| Databáze: | OpenAIRE |
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