1GYK

Serum Amyloid P Component co-crystallised with MOBDG at neutral pH

Summary for 1GYK

• Entry DOI: 10.2210/pdb1gyk/pdb
• Related: 1LGN 1SAC
• Descriptor: SERUM AMYLOID P-COMPONENT, CALCIUM ION, METHYL 4,6-O-[(1R)-1-CARBOXYETHYLIDENE]-BETA-D-GALACTOPYRANOSIDE (3 entities in total)
• Functional Keywords: pentraxin, amyloid lectin, glycoprotein, plasma, polymorphism
• Biological source: HOMO SAPIENS (HUMAN)
• Cellular location: Secreted: P02743
• Total number of polymer chains: 5
• Total formula weight: 117829.89

Authors

Thompson, D.,Pepys, M.B.,Tickle, I.,Wood, S.P. (deposition date: 2002-04-25, release date: 2003-05-22, Last modification date: 2024-11-13)

Primary citation

Thompson, D.,Pepys, M.B.,Tickle, I.,Wood, S.P.
The Structures of Crystalline Complexes of Human Serum Amyloid P Component with its Carbohydrate Ligand, the Cyclic Pyruvate Acetal of Galactose
J.Mol.Biol., 320:1081-, 2002

PubMed Abstract: Two monoclinic (P2(1)) crystal forms of human serum amyloid P component (SAP) in complex with the 4,6-pyruvate acetal of beta-D-galactose (MObetaDG) were prepared. Structure analysis by molecular replacement and refinement at 2.2A resolution revealed that crystal form 1 (a=95.76A, b=70.53A, c=103.41A, beta=96.80 degrees) contained a pentamer in the asymmetric unit with a structure very similar to that of the published search model. The mode of ligand co-ordination was also similar except that four of the five subunits showed bound ligand with an additional H-bond between O1 of the galactose and the side-chain of Lys79. One sub-unit showed no bound ligand and a vacant calcium site close to a crystal contact. The 2.6A resolution structure of crystal form 2 (a=118.60A, b=109.10A, c=120.80A and beta=95.16 degrees ) showed ten sub-units in the asymmetric unit, all with two bound calcium ions and ligand. The most extensive protein-protein interactions between pentamers describe an AB face-to-face interaction involving 15 ion pairs that sandwiches five molecules of bound MObetaDG at the interface.

PubMed: 12126626
DOI: 10.1016/S0022-2836(02)00514-4

Experimental method

X-RAY DIFFRACTION (2.2 Å)