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1mkx
From Proteopedia
THE CO-CRYSTAL STRUCTURE OF UNLIGANDED BOVINE ALPHA-THROMBIN AND PRETHROMBIN-2: MOVEMENT OF THE YPPW SEGMENT AND ACTIVE SITE RESIDUES UPON LIGAND BINDING
Overview
Unliganded bovine alpha-thrombin and prethrombin-2 have been co-crystallized, in space group P21212, using either ammonium sulfate or polyethylene glycol 2000 (PEG2K), and their structures determined at 2.2 A and 2.3 A, respectively. Initial phases were determined by molecular replacement and refined using XPLOR to final R factors of 0.187 (Rfree = 0.255) and 0.190 (Rfree = 0.282) for the salt and PEG2K models, respectively. The apo-enzyme form of bovine alpha-thrombin shows dramatic shifts in placement for the Tyr-Pro-Pro-Trp segment, for Glu-192, and for the catalytic residues His-57 and Ser-195, when compared to 4 thrombin complexes representing different states of catalysis, namely (1) the Michaelis complex (residues 7-19 of fibrinogen A alpha with a non-cleavable scissile bond), (2) enzyme-inhibitor complex (D-Phe-Pro-Arg chloromethylketone), (3) enzyme product complex (residues 7-16 of fibrinopeptide A), and (4) the exosite complex (residues 53-64 of hirudin). The structures of bovine and human prethrombin-2 are generally similar to one another (RMS deviation of 0.68 A) but differ significantly in the Arg-15/Ile-16 cleavage region and in the three activation domains, which are disordered in bovine prethrombin-2, analogous to that seen for trypsinogen.
About this Structure
1MKX is a Protein complex structure of sequences from Bos taurus. The following page contains interesting information on the relation of 1MKX with [Thrombin]. Full crystallographic information is available from OCA.
Reference
The co-crystal structure of unliganded bovine alpha-thrombin and prethrombin-2: movement of the Tyr-Pro-Pro-Trp segment and active site residues upon ligand binding., Malkowski MG, Martin PD, Guzik JC, Edwards BF, Protein Sci. 1997 Jul;6(7):1438-48. PMID:9232645 Page seeded by OCA on Sat May 3 01:20:26 2008
