1QMO

Structure of FRIL, a legume lectin that delays hematopoietic progenitor maturation

Summary for 1QMO

• Entry DOI: 10.2210/pdb1qmo/pdb
• Descriptor: MANNOSE BINDING LECTIN, FRIL, CALCIUM ION, MANGANESE (II) ION, ... (5 entities in total)
• Functional Keywords: lectin, crosslink, hematopoietic progenitor, sugar complex
• Biological source: DOLICHOS LAB LAB (FIELD BEAN); More
• Total number of polymer chains: 8
• Total formula weight: 109905.05

Authors

Hamelryck, T.W.,Moore, J.G.,Chrispeels, M.,Loris, R.,Wyns, L. (deposition date: 1999-10-04, release date: 1999-10-10, Last modification date: 2024-05-08)

Primary citation

Hamelryck, T.W.,Moore, J.G.,Chrispeels, M.J.,Loris, R.,Wyns, L.
The Role of Weak Protein-Protein Interactions in Multivalent Lectin-Carbohydrate Binding: Crystal Structure of Cross-Linked Fril
J.Mol.Biol., 299:875-, 2000

PubMed Abstract: Binding of multivalent glycoconjugates by lectins often leads to the formation of cross-linked complexes. Type I cross-links, which are one-dimensional, are formed by a divalent lectin and a divalent glycoconjugate. Type II cross-links, which are two or three-dimensional, occur when a lectin or glycoconjugate has a valence greater than two. Type II complexes are a source of additional specificity, since homogeneous type II complexes are formed in the presence of mixtures of lectins and glycoconjugates. This additional specificity is thought to become important when a lectin interacts with clusters of glycoconjugates, e.g. as is present on the cell surface. The cryst1al structure of the Glc/Man binding legume lectin FRIL in complex with a trisaccharide provides a molecular snapshot of how weak protein-protein interactions, which are not observed in solution, can become important when a cross-linked complex is formed. In solution, FRIL is a divalent dimer, but in the crystal FRIL forms a tetramer, which allows for the formation of an intricate type II cross-linked complex with the divalent trisaccharide. The dependence on weak protein-protein interactions can ensure that a specific type II cross-linked complex and its associated specificity can occur only under stringent conditions, which explains why lectins are often found forming higher-order oligomers.

PubMed: 10843844
DOI: 10.1006/JMBI.2000.3785

Experimental method

X-RAY DIFFRACTION (3.5 Å)