3sgb
From Proteopedia
(New page: 200px<br /><applet load="3sgb" size="450" color="white" frame="true" align="right" spinBox="true" caption="3sgb, resolution 1.8Å" /> '''STRUCTURE OF THE COMP...) |
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| - | [[Image:3sgb.jpg|left|200px]]<br /><applet load="3sgb" size=" | + | [[Image:3sgb.jpg|left|200px]]<br /><applet load="3sgb" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="3sgb, resolution 1.8Å" /> | caption="3sgb, resolution 1.8Å" /> | ||
'''STRUCTURE OF THE COMPLEX OF STREPTOMYCES GRISEUS PROTEASE B AND THE THIRD DOMAIN OF THE TURKEY OVOMUCOID INHIBITOR AT 1.8 ANGSTROMS RESOLUTION'''<br /> | '''STRUCTURE OF THE COMPLEX OF STREPTOMYCES GRISEUS PROTEASE B AND THE THIRD DOMAIN OF THE TURKEY OVOMUCOID INHIBITOR AT 1.8 ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of the complex between the serine protease Streptomyces | + | The structure of the complex between the serine protease Streptomyces griseus protease B (SGPB) and the third domain of the Kazal-type ovomucoid inhibitor from turkey has been solved at 1.8-A resolution and refined to a conventional R factor of 0.125. As others have reported previously for analogous complexes of proteases and protein inhibitors, the inhibitor binds in a fashion similar to that of a substrate; it is not cleaved, but there is a close approach (2.7 A) of the active site nucleophile Ser-195 O gamma to the carbonyl carbon of the reactive peptide bond of the inhibitor. Contrary to the structural reports regarding the other enzyme-inhibitor complexes, we conclude that there is no evidence for a significant distortion of this peptide bond from planarity. The mechanism of inhibition can be understood in terms of the equilibrium thermodynamic parameters Ka, the enzyme-inhibitor association constant, and Khyd, the equilibrium constant for inhibitor hydrolysis. These thermodynamic parameters can be rationalized in terms of the observed structure. |
==About this Structure== | ==About this Structure== | ||
| - | 3SGB is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Streptomyces_chryseus Streptomyces chryseus]. This structure | + | 3SGB is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Streptomyces_chryseus Streptomyces chryseus]. This structure supersedes the now removed PDB entries 2SGB and 1SGB. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3SGB OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Streptomyces chryseus]] | [[Category: Streptomyces chryseus]] | ||
[[Category: Fujinaga, M.]] | [[Category: Fujinaga, M.]] | ||
| - | [[Category: James, M | + | [[Category: James, M N.G.]] |
| - | [[Category: Read, R | + | [[Category: Read, R J.]] |
| - | [[Category: Sielecki, A | + | [[Category: Sielecki, A R.]] |
[[Category: complex(serine proteinase-inhibitor)]] | [[Category: complex(serine proteinase-inhibitor)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:11:20 2008'' |
Revision as of 17:11, 21 February 2008
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STRUCTURE OF THE COMPLEX OF STREPTOMYCES GRISEUS PROTEASE B AND THE THIRD DOMAIN OF THE TURKEY OVOMUCOID INHIBITOR AT 1.8 ANGSTROMS RESOLUTION
Overview
The structure of the complex between the serine protease Streptomyces griseus protease B (SGPB) and the third domain of the Kazal-type ovomucoid inhibitor from turkey has been solved at 1.8-A resolution and refined to a conventional R factor of 0.125. As others have reported previously for analogous complexes of proteases and protein inhibitors, the inhibitor binds in a fashion similar to that of a substrate; it is not cleaved, but there is a close approach (2.7 A) of the active site nucleophile Ser-195 O gamma to the carbonyl carbon of the reactive peptide bond of the inhibitor. Contrary to the structural reports regarding the other enzyme-inhibitor complexes, we conclude that there is no evidence for a significant distortion of this peptide bond from planarity. The mechanism of inhibition can be understood in terms of the equilibrium thermodynamic parameters Ka, the enzyme-inhibitor association constant, and Khyd, the equilibrium constant for inhibitor hydrolysis. These thermodynamic parameters can be rationalized in terms of the observed structure.
About this Structure
3SGB is a Protein complex structure of sequences from Streptomyces chryseus. This structure supersedes the now removed PDB entries 2SGB and 1SGB. Full crystallographic information is available from OCA.
Reference
Structure of the complex of Streptomyces griseus protease B and the third domain of the turkey ovomucoid inhibitor at 1.8-A resolution., Read RJ, Fujinaga M, Sielecki AR, James MN, Biochemistry. 1983 Sep 13;22(19):4420-33. PMID:6414511
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