1pj8
From Proteopedia
(New page: 200px<br /><applet load="1pj8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1pj8, resolution 2.2Å" /> '''Structure of a ternar...) |
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| - | [[Image:1pj8.gif|left|200px]]<br /><applet load="1pj8" size=" | + | [[Image:1pj8.gif|left|200px]]<br /><applet load="1pj8" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1pj8, resolution 2.2Å" /> | caption="1pj8, resolution 2.2Å" /> | ||
'''Structure of a ternary complex of proteinase K, mercury and a substrate-analogue hexapeptide at 2.2 A resolution'''<br /> | '''Structure of a ternary complex of proteinase K, mercury and a substrate-analogue hexapeptide at 2.2 A resolution'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of a ternary complex of proteinase K, Hg(II) and a | + | The crystal structure of a ternary complex of proteinase K, Hg(II) and a hexapeptide N-Ac-Pro-Ala-Pro-Phe-Pro-Ala-NH2 has been determined at 2.2 A resolution and refined to an R factor of 0.172 for 12,910 reflections. The mercury atom occupies two alternate sites, each of which was assigned an occupancy of 0.45. These two sites are bridged by Cys-73 S gamma which forms covalent bonds to both. Both mercury sites form regular polyhedrons involving atoms from residues Asp-39, His-69, Cys-73, His-72, Met-225, and Wat-324. The complex formation with mercury seems to disturb the stereochemistry of the residues of the catalytic triad Asp-39, His-69, and Ser-224 appreciably, thus reducing the enzymatic activity of proteinase K to 15%. The electron density in the difference Fourier map shows that the hexapeptide occupies the S1 subsite predominantly and the standard recognition site constituted by Ser-132 to Gly-136 and Gly-100 to Tyr-104 segments is virtually empty. The hexapeptide is held firmly through a series of hydrogen bonds involving protein atoms and water molecules. As a result of complex formation, Asp-39, His-69, Met-225, Ile-220, Ser-219, Thr-223, and Ser-224 residues move appreciably to accommodate the mercury atoms and the hexapeptide. The largest movement is observed for Met-225 which is involved in multiple interactions with both mercury and the hexapeptide. The activity results indicate an inhibition rate of 95%, as a result of the combined effect of mercury and hexapeptide. |
==About this Structure== | ==About this Structure== | ||
| - | 1PJ8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Engyodontium_album Engyodontium album] with HG and NH2 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http:// | + | 1PJ8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Engyodontium_album Engyodontium album] with <scene name='pdbligand=HG:'>HG</scene> and <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PJ8 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Fittkau, S.]] | [[Category: Fittkau, S.]] | ||
[[Category: Peters, K.]] | [[Category: Peters, K.]] | ||
| - | [[Category: Saxena, A | + | [[Category: Saxena, A K.]] |
| - | [[Category: Singh, T | + | [[Category: Singh, T P.]] |
[[Category: Visanji, M.]] | [[Category: Visanji, M.]] | ||
| - | [[Category: Wilson, K | + | [[Category: Wilson, K S.]] |
[[Category: HG]] | [[Category: HG]] | ||
[[Category: NH2]] | [[Category: NH2]] | ||
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[[Category: ternary complex]] | [[Category: ternary complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:29:20 2008'' |
Revision as of 12:29, 21 February 2008
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Structure of a ternary complex of proteinase K, mercury and a substrate-analogue hexapeptide at 2.2 A resolution
Overview
The crystal structure of a ternary complex of proteinase K, Hg(II) and a hexapeptide N-Ac-Pro-Ala-Pro-Phe-Pro-Ala-NH2 has been determined at 2.2 A resolution and refined to an R factor of 0.172 for 12,910 reflections. The mercury atom occupies two alternate sites, each of which was assigned an occupancy of 0.45. These two sites are bridged by Cys-73 S gamma which forms covalent bonds to both. Both mercury sites form regular polyhedrons involving atoms from residues Asp-39, His-69, Cys-73, His-72, Met-225, and Wat-324. The complex formation with mercury seems to disturb the stereochemistry of the residues of the catalytic triad Asp-39, His-69, and Ser-224 appreciably, thus reducing the enzymatic activity of proteinase K to 15%. The electron density in the difference Fourier map shows that the hexapeptide occupies the S1 subsite predominantly and the standard recognition site constituted by Ser-132 to Gly-136 and Gly-100 to Tyr-104 segments is virtually empty. The hexapeptide is held firmly through a series of hydrogen bonds involving protein atoms and water molecules. As a result of complex formation, Asp-39, His-69, Met-225, Ile-220, Ser-219, Thr-223, and Ser-224 residues move appreciably to accommodate the mercury atoms and the hexapeptide. The largest movement is observed for Met-225 which is involved in multiple interactions with both mercury and the hexapeptide. The activity results indicate an inhibition rate of 95%, as a result of the combined effect of mercury and hexapeptide.
About this Structure
1PJ8 is a Single protein structure of sequence from Engyodontium album with and as ligands. Active as Peptidase K, with EC number 3.4.21.64 Full crystallographic information is available from OCA.
Reference
Structure of a ternary complex of proteinase K, mercury, and a substrate-analogue hexa-peptide at 2.2 A resolution., Saxena AK, Singh TP, Peters K, Fittkau S, Visanji M, Wilson KS, Betzel C, Proteins. 1996 Jun;25(2):195-201. PMID:8811735
Page seeded by OCA on Thu Feb 21 14:29:20 2008
Categories: Engyodontium album | Peptidase K | Single protein | Betzel, C. | Fittkau, S. | Peters, K. | Saxena, A K. | Singh, T P. | Visanji, M. | Wilson, K S. | HG | NH2 | Inhibitor | Mercury | Proteinase k | Structure | Ternary complex
