1afa: Difference between revisions
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[[Image:1afa.gif|left|200px]] | [[Image:1afa.gif|left|200px]] | ||
'''STRUCTURAL BASIS OF GALACTOSE RECOGNITION IN C-TYPE ANIMAL LECTINS''' | {{Structure | ||
|PDB= 1afa |SIZE=350|CAPTION= <scene name='initialview01'>1afa</scene>, resolution 2.0Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=MBG:METHYL-BETA-GALACTOSE'>MBG</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> and <scene name='pdbligand=CL:CHLORIDE ION'>CL</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''STRUCTURAL BASIS OF GALACTOSE RECOGNITION IN C-TYPE ANIMAL LECTINS''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1AFA is a [ | 1AFA is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AFA OCA]. | ||
==Reference== | ==Reference== | ||
Structural basis of galactose recognition by C-type animal lectins., Kolatkar AR, Weis WI, J Biol Chem. 1996 Mar 22;271(12):6679-85. PMID:[http:// | Structural basis of galactose recognition by C-type animal lectins., Kolatkar AR, Weis WI, J Biol Chem. 1996 Mar 22;271(12):6679-85. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8636086 8636086] | ||
[[Category: Rattus norvegicus]] | [[Category: Rattus norvegicus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: calcium-binding protein]] | [[Category: calcium-binding protein]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 09:56:42 2008'' | ||
Revision as of 10:56, 20 March 2008
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
STRUCTURAL BASIS OF GALACTOSE RECOGNITION IN C-TYPE ANIMAL LECTINS
OverviewOverview
The asialoglycoprotein receptors and many other C-type (Ca2+-dependent) animal lectins specifically recognize galactose- or N-acetylgalactosamine-terminated oligosaccharides. Analogous binding specificity can be engineered into the homologous rat mannose-binding protein A by changing three amino acids and inserting a glycine-rich loop (Iobst, S. T., and Drickamer, K. (1994) J. Biol. Chem. 269, 15512-15519). Crystal structures of this mutant complexed with beta-methyl galactoside and N-acetylgalactosamine (GalNAc) reveal that as with wild-type mannose-binding proteins, the 3- and 4-OH groups of the sugar directly coordinate Ca2+ and form hydrogen bonds with amino acids that also serve as Ca2+ ligands. The different stereochemistry of the 3- and 4-OH groups in mannose and galactose, combined with a fixed Ca2+ coordination geometry, leads to different pyranose ring locations in the two cases. The glycine-rich loop provides selectivity against mannose by holding a critical tryptophan in a position optimal for packing with the apolar face of galactose but incompatible with mannose binding. The 2-acetamido substituent of GalNAc is in the vicinity of amino acid positions identified by site-directed mutagenesis (Iobst, S. T., and Drickamer, K. (1996) J. Biol. Chem. 271, 6686-6693) as being important for the formation of a GalNAc-selective binding site.
About this StructureAbout this Structure
1AFA is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis of galactose recognition by C-type animal lectins., Kolatkar AR, Weis WI, J Biol Chem. 1996 Mar 22;271(12):6679-85. PMID:8636086
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