1gyk
From Proteopedia
SERUM AMYLOID P COMPONENT CO-CRYSTALLISED WITH MOBDG AT NEUTRAL PH
Overview
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.
About this Structure
1GYK is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The structures of crystalline complexes of human serum amyloid P component with its carbohydrate ligand, the cyclic pyruvate acetal of galactose., Thompson D, Pepys MB, Tickle I, Wood S, J Mol Biol. 2002 Jul 26;320(5):1081-6. PMID:12126626 Page seeded by OCA on Fri May 2 18:11:00 2008
