1qmo: Difference between revisions
New page: left|200px<br /><applet load="1qmo" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qmo, resolution 3.5Å" /> '''STRUCTURE OF FRIL, A ... |
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[[Image:1qmo.jpg|left|200px]]<br /><applet load="1qmo" size=" | [[Image:1qmo.jpg|left|200px]]<br /><applet load="1qmo" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1qmo, resolution 3.5Å" /> | caption="1qmo, resolution 3.5Å" /> | ||
'''STRUCTURE OF FRIL, A LEGUME LECTIN THAT DELAYS HEMATOPOIETIC PROGENITOR MATURATION'''<br /> | '''STRUCTURE OF FRIL, A LEGUME LECTIN THAT DELAYS HEMATOPOIETIC PROGENITOR MATURATION'''<br /> | ||
==Overview== | ==Overview== | ||
Binding of multivalent glycoconjugates by lectins often leads to the | 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. | ||
==About this Structure== | ==About this Structure== | ||
1QMO is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Lablab_purpureus Lablab purpureus] with MAN, CA and MN as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1QMO is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Lablab_purpureus Lablab purpureus] with <scene name='pdbligand=MAN:'>MAN</scene>, <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=MN:'>MN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QMO OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Chrispeels, M.]] | [[Category: Chrispeels, M.]] | ||
[[Category: Hamelryck, T | [[Category: Hamelryck, T W.]] | ||
[[Category: Loris, R.]] | [[Category: Loris, R.]] | ||
[[Category: Moore, J | [[Category: Moore, J G.]] | ||
[[Category: Wyns, L.]] | [[Category: Wyns, L.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: sugar complex]] | [[Category: sugar complex]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:41:22 2008'' | ||
Revision as of 12:41, 21 February 2008
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STRUCTURE OF FRIL, A LEGUME LECTIN THAT DELAYS HEMATOPOIETIC PROGENITOR MATURATION
Overview
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.
About this Structure
1QMO is a Protein complex structure of sequences from Lablab purpureus with MAN, CA and MN as ligands. Full crystallographic information is available from OCA.
Reference
The role of weak protein-protein interactions in multivalent lectin-carbohydrate binding: crystal structure of cross-linked FRIL., Hamelryck TW, Moore JG, Chrispeels MJ, Loris R, Wyns L, J Mol Biol. 2000 Jun 16;299(4):875-83. PMID:10843844
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