1ptk: Difference between revisions

Revision as of 05:28, 3 May 2008

STUDIES ON THE INHIBITORY ACTION OF MERCURY UPON PROTEINASE K

OverviewOverview

In proteinase K, Cys73 is located "below" the imidazole of the active site His69. In a 2.4-A resolution x-ray crystal structure of the complex formed between the enzyme and HgAc2, two Hg(II) positions are found: a fully occupied site, covalently bound to Cys73 (S gamma), which disrupts the catalytic triad (Asp39-His69-Ser224), and a 2-fold disordered (25 and 35% occupancy), noncovalent complexation to His72, Cys73, and Thr76 of lower affinity. The enzyme is inhibited noncompetitively at low concentrations and competitively above stoichiometric concentrations of Hg(II), but it retains 7% residual activity. This can be rationalized if the molecule is flexible enough to permit transient formation of the catalytic triad. Except for the active site, only minor structural changes are observed upon binding of Hg(II), but the thermal stability is reduced by 4 degrees C.

About this StructureAbout this Structure

1PTK is a Single protein structure of sequence from Engyodontium album. Full crystallographic information is available from OCA.

ReferenceReference

Studies on the inhibitory action of mercury upon proteinase K., Muller A, Saenger W, J Biol Chem. 1993 Dec 15;268(35):26150-4. PMID:8253733 Page seeded by OCA on Sat May 3 05:28:16 2008

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OCA

@@ Line 1: / Line 1: @@
 [[Image:1ptk.jpg|left|200px]]
- {{Structure
+<!--
-|PDB= 1ptk |SIZE=350|CAPTION= <scene name='initialview01'>1ptk</scene>, resolution 2.4&Aring;
+The line below this paragraph, containing "STRUCTURE_1ptk", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=HG:MERCURY+(II)+ION'>HG</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Peptidase_K Peptidase K], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.64 3.4.21.64] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1ptk|  PDB=1ptk  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ptk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ptk OCA], [http://www.ebi.ac.uk/pdbsum/1ptk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ptk RCSB]</span>
-}}
 '''STUDIES ON THE INHIBITORY ACTION OF MERCURY UPON PROTEINASE K'''
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 [[Category: Mueller, A.]]
 [[Category: Saenger, W.]]
-[[Category: hydrolase(serine proteinase)]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 05:28:16 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:04:23 2008''