1ptk

STUDIES ON THE INHIBITORY ACTION OF MERCURY UPON PROTEINASE K

spinqualitylabelsall models 1ptk, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ptk is a 1 chain structure with sequence from Beauveria alba. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CA, HG Activity: Peptidase K, with EC number 3.4.21.64 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PRTK_TRIAL] Hydrolyzes keratin at aromatic and hydrophobic residues. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed 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. 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Proteinase

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