1mkx
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THE CO-CRYSTAL STRUCTURE OF UNLIGANDED BOVINE ALPHA-THROMBIN AND PRETHROMBIN-2: MOVEMENT OF THE YPPW SEGMENT AND ACTIVE SITE RESIDUES UPON LIGAND BINDING
OverviewOverview
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 StructureAbout 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]. Active as Thrombin, with EC number 3.4.21.5 Full crystallographic information is available from OCA.
ReferenceReference
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
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