1rdk: Difference between revisions

Revision as of 07:21, 3 May 2008

MANNOSE-BINDING PROTEIN, SUBTILISIN DIGEST FRAGMENT COMPLEX WITH D-GALACTOSE

OverviewOverview

The structural basis of carbohydrate recognition by rat liver mannose-binding protein (MBP-C) has been explored by determining the three-dimensional structure of the C-type carbohydrate-recognition domain (CRD) of MBP-C using x-ray crystallography. The structure was solved by molecular replacement using rat serum mannose-binding protein (MBP-A) as a search model and was refined to maximum Bragg spacings of 1.7 A. Despite their almost identical folds, the dimeric structures formed by the two MBP CRDs differ dramatically. Complexes of MBP-C with methyl glycosides of mannose, N-acetylglucosamine, and fucose were prepared by soaking MBP-C crystals in solutions containing these sugars. Surprisingly, the pyranose ring of mannose is rotated 180 degrees relative to the orientation observed previously in MBP-A, but the local interactions between sugar and protein are preserved. For each of the bound sugars, vicinal, equatorial hydroxyl groups equivalent to the 3- and 4-OH groups of mannose directly coordinate Ca2+ and form hydrogen bonds with residues also serving as Ca2+ ligands. Few interactions are observed between other parts of the sugar and the protein. A complex formed between free galactose and MBP-C reveals a similar mode of binding, with the anomeric hydroxyl group serving as one of the Ca2+ ligands. A second binding site for mannose has also been observed in one of two copies in the asymmetric unit at a sugar concentration of 1.3 M. These structures explain how MBPs recognize a wide range of monosaccharides and suggest how fine specificity differences between MBP-A and MBP-C may be achieved.

About this StructureAbout this Structure

1RDK is a Single protein structure of sequence from Rattus rattus. Full crystallographic information is available from OCA.

ReferenceReference

Structural analysis of monosaccharide recognition by rat liver mannose-binding protein., Ng KK, Drickamer K, Weis WI, J Biol Chem. 1996 Jan 12;271(2):663-74. PMID:8557671 Page seeded by OCA on Sat May 3 07:21:56 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
 [[Image:1rdk.jpg|left|200px]]
- {{Structure
+<!--
-|PDB= 1rdk |SIZE=350|CAPTION= <scene name='initialview01'>1rdk</scene>, resolution 1.8&Aring;
+The line below this paragraph, containing "STRUCTURE_1rdk", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY=
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1rdk|  PDB=1rdk  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1rdk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1rdk OCA], [http://www.ebi.ac.uk/pdbsum/1rdk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1rdk RCSB]</span>
-}}
 '''MANNOSE-BINDING PROTEIN, SUBTILISIN DIGEST FRAGMENT COMPLEX WITH D-GALACTOSE'''
@@ Line 28: / Line 25: @@
 [[Category: Ng, K K.S.]]
 [[Category: Weis, W I.]]
-[[Category: c-type lectin]]
+[[Category: C-type lectin]]
-[[Category: calcium-binding protein]]
+[[Category: Calcium-binding protein]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 07:21:56 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:26:40 2008''