2pgq
From Proteopedia
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</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2pgq ConSurf]. | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2pgq ConSurf]. | ||
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- | == Publication Abstract from PubMed == | ||
- | Little is known on the role of disulfide bonds in the catalytic domain of serine proteases. The Cys-191-Cys-220 disulfide bond is located between the 190 strand leading to the oxyanion hole and the 220-loop that contributes to the architecture of the primary specificity pocket and the Na+ binding site in allosteric proteases. Removal of this bond in thrombin produces an approximately 100-fold loss of activity toward several chromogenic and natural substrates carrying Arg or Lys at P1. Na+ activation is compromised, and no fluorescence change can be detected in response to Na+ binding. A 1.54-A resolution structure of the C191A/C220A mutant in the free form reveals a conformation similar to the Na+-free slow form of wild type. The lack of disulfide bond exposes the side chain of Asp-189 to solvent, flips the backbone O atom of Gly-219, and generates disorder in portions of the 186 and 220 loops defining the Na+ site. This conformation, featuring perturbation of the Na+ site but with the active site accessible to substrate, offers a possible representation of the recently identified E* form of thrombin. Disorder in the 186 and 220 loops and the flip of Gly-219 are corrected by the active site inhibitor H-D-Phe-Pro-Arg-CH(2)Cl, as revealed by the 1.8-A resolution structure of the complex. We conclude that the Cys-191-Cys-220 disulfide bond confers stability to the primary specificity pocket by shielding Asp-189 from the solvent and orients the backbone O atom of Gly-219 for optimal substrate binding. In addition, the disulfide bond stabilizes the 186 and 220 loops that are critical for Na+ binding and activation. | ||
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- | Important role of the cys-191 cys-220 disulfide bond in thrombin function and allostery.,Bush-Pelc LA, Marino F, Chen Z, Pineda AO, Mathews FS, Di Cera E J Biol Chem. 2007 Sep 14;282(37):27165-70. Epub 2007 Jul 18. PMID:17636263<ref>PMID:17636263</ref> | ||
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- | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
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- | <div class="pdbe-citations 2pgq" style="background-color:#fffaf0;"></div> | ||
==See Also== | ==See Also== |
Revision as of 13:53, 13 March 2024
Human thrombin mutant C191A-C220A in complex with the inhibitor PPACK
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Categories: Homo sapiens | Large Structures | Bush-Pelc LA | Chen Z | Di Cera E | Marino F | Mathews FS | Pineda AO