4H6S
Crystal structure of thrombin mutant E14eA/D14lA/E18A/S195A
Summary for 4H6S
| Entry DOI | 10.2210/pdb4h6s/pdb |
| Related | 1SHH 4H6T |
| Descriptor | Prothrombin, SODIUM ION, ... (4 entities in total) |
| Functional Keywords | serine protease, prethrombin-2, autoactivation, hydrolase, hydrolase-peptide complex, hydrolase/peptide |
| Biological source | Homo sapiens (human) More |
| Cellular location | Secreted, extracellular space: P00734 P00734 |
| Total number of polymer chains | 2 |
| Total formula weight | 33274.20 |
| Authors | Pozzi, N.,Chen, Z.,Zapata, F.,Pelc, L.A.,Di Cera, E. (deposition date: 2012-09-19, release date: 2013-03-13, Last modification date: 2024-11-27) |
| Primary citation | Pozzi, N.,Chen, Z.,Zapata, F.,Niu, W.,Barranco-Medina, S.,Pelc, L.A.,Di Cera, E. Autoactivation of thrombin precursors. J.Biol.Chem., 288:11601-11610, 2013 Cited by PubMed Abstract: Trypsin-like proteases are synthesized as inactive zymogens and convert to the mature form upon activation by specific enzymes, often assisted by cofactors. Central to this paradigm is that the zymogen does not convert spontaneously to the mature enzyme, which in turn does not feed back to activate its zymogen form. In the blood, the zymogens prothrombin and prethrombin-2 require the prothrombinase complex to be converted to the mature protease thrombin, which is unable to activate prothrombin or prethrombin-2. Here, we show that replacement of key residues within the activation domain causes these zymogens to spontaneously convert to thrombin. The conversion is started by the zymogen itself, which is capable of binding ligands at the active site, and is abrogated by inactivation of the catalytic residue Ser-195. The product of autoactivation is functionally and structurally equivalent to wild-type thrombin. Zymogen autoactivation is explained by conformational selection, a basic property of the trypsin fold uncovered by structural and rapid kinetics studies. Both the zymogen and protease undergo a pre-existing equilibrium between active and inactive forms. The equilibrium regulates catalytic activity in the protease and has the potential to unleash activity in the zymogen to produce autoactivation. A new strategy emerges for the facile production of enzymes through zymogen autoactivation that is broadly applicable to trypsin-like proteases of biotechnological and clinical interest. PubMed: 23467412DOI: 10.1074/jbc.M113.451542 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.19 Å) |
Structure validation
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