1fif: Difference between revisions
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'''N-ACETYLGALACTOSAMINE-SELECTIVE MUTANT OF MANNOSE-BINDING PROTEIN-A (QPDWG-HDRPY)''' | {{Structure | ||
|PDB= 1fif |SIZE=350|CAPTION= <scene name='initialview01'>1fif</scene>, resolution 1.95Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> and <scene name='pdbligand=CL:CHLORIDE ION'>CL</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''N-ACETYLGALACTOSAMINE-SELECTIVE MUTANT OF MANNOSE-BINDING PROTEIN-A (QPDWG-HDRPY)''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1FIF is a [ | 1FIF 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=1FIF OCA]. | ||
==Reference== | ==Reference== | ||
Mechanism of pH-dependent N-acetylgalactosamine binding by a functional mimic of the hepatocyte asialoglycoprotein receptor., Feinberg H, Torgersen D, Drickamer K, Weis WI, J Biol Chem. 2000 Nov 10;275(45):35176-84. PMID:[http:// | Mechanism of pH-dependent N-acetylgalactosamine binding by a functional mimic of the hepatocyte asialoglycoprotein receptor., Feinberg H, Torgersen D, Drickamer K, Weis WI, J Biol Chem. 2000 Nov 10;275(45):35176-84. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10931846 10931846] | ||
[[Category: Rattus norvegicus]] | [[Category: Rattus norvegicus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: lectin]] | [[Category: lectin]] | ||
''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 11:09:31 2008'' | ||
Revision as of 09:09, 20 March 2008
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| 1fif, resolution 1.95Å | |||||||||||||
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| Ligands: | CA and CL | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
N-ACETYLGALACTOSAMINE-SELECTIVE MUTANT OF MANNOSE-BINDING PROTEIN-A (QPDWG-HDRPY)
Overview
Efficient release of ligands from the Ca(2+)-dependent carbohydrate-recognition domain (CRD) of the hepatic asialoglycoprotein receptor at endosomal pH requires a small set of conserved amino acids that includes a critical histidine residue. When these residues are incorporated at corresponding positions in an homologous galactose-binding derivative of serum mannose-binding protein, the pH dependence of ligand binding becomes more like that of the receptor. The modified CRD displays 40-fold preferential binding to N-acetylgalactosamine compared with galactose, making it a good functional mimic of the asialoglycoprotein receptor. In the crystal structure of the modified CRD bound to N-acetylgalactosamine, the histidine (His(202)) contacts the 2-acetamido methyl group and also participates in a network of interactions involving Asp(212), Arg(216), and Tyr(218) that positions a water molecule in a hydrogen bond with the sugar amide group. These interactions appear to produce the preference for N-acetylgalactosamine over galactose and are also likely to influence the pK(a) of His(202). Protonation of His(202) would disrupt its interaction with an asparagine that serves as a ligand for Ca(2+) and sugar. The structure of the modified CRD without sugar displays several different conformations that may represent structures of intermediates in the release of Ca(2+) and sugar ligands caused by protonation of His(202).
About this Structure
1FIF is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
Mechanism of pH-dependent N-acetylgalactosamine binding by a functional mimic of the hepatocyte asialoglycoprotein receptor., Feinberg H, Torgersen D, Drickamer K, Weis WI, J Biol Chem. 2000 Nov 10;275(45):35176-84. PMID:10931846
Page seeded by OCA on Thu Mar 20 11:09:31 2008
