1MKW:
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

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