1qz3
From Proteopedia
(New page: 200px<br /><applet load="1qz3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qz3, resolution 2.30Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1qz3.gif|left|200px]]<br /><applet load="1qz3" size=" | + | [[Image:1qz3.gif|left|200px]]<br /><applet load="1qz3" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qz3, resolution 2.30Å" /> | caption="1qz3, resolution 2.30Å" /> | ||
'''CRYSTAL STRUCTURE OF MUTANT M211S/R215L OF CARBOXYLESTERASE EST2 COMPLEXED WITH HEXADECANESULFONATE'''<br /> | '''CRYSTAL STRUCTURE OF MUTANT M211S/R215L OF CARBOXYLESTERASE EST2 COMPLEXED WITH HEXADECANESULFONATE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The reaction mechanism of the esterase 2 (EST2) from Alicyclobacillus | + | The reaction mechanism of the esterase 2 (EST2) from Alicyclobacillus acidocaldarius was studied at the kinetic and structural level to shed light on the mechanism of activity and substrate specificity increase previously observed in its double mutant M211S/R215L. In particular, the values of kinetic constants (k1, k(-1), k2, and k3) along with activation energies (E1, E(-1), E2, and E3) were measured for wild type and mutant enzyme. The previously suggested substrate-induced switch in the reaction mechanism from kcat=k3 with a short acyl chain substrate (p-nitrophenyl hexanoate) to kcat=k2 with a long acyl chain substrate (p-nitrophenyl dodecanoate) was validated. The inhibition afforded by an irreversible inhibitor (1-hexadecanesulfonyl chloride), structurally related to p-nitrophenyl dodecanoate, was studied by kinetic analysis. Moreover the three-dimensional structure of the double mutant bound to this inhibitor was determined, providing essential information on the enzyme mechanism. In fact, structural analysis explained the observed substrate-induced switch because of an inversion in the binding mode of the long acyl chain derivatives with respect to the acyl- and alcohol-binding sites. |
==About this Structure== | ==About this Structure== | ||
| - | 1QZ3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Alicyclobacillus_acidocaldarius Alicyclobacillus acidocaldarius] with HDS as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Carboxylesterase Carboxylesterase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.1 3.1.1.1] Full crystallographic information is available from [http:// | + | 1QZ3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Alicyclobacillus_acidocaldarius Alicyclobacillus acidocaldarius] with <scene name='pdbligand=HDS:'>HDS</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Carboxylesterase Carboxylesterase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.1 3.1.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QZ3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Pedone, C.]] | [[Category: Pedone, C.]] | ||
[[Category: Rossi, M.]] | [[Category: Rossi, M.]] | ||
| - | [[Category: Simone, G | + | [[Category: Simone, G De.]] |
[[Category: HDS]] | [[Category: HDS]] | ||
[[Category: alpha/beta hydrolase fold]] | [[Category: alpha/beta hydrolase fold]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:45:22 2008'' |
Revision as of 12:45, 21 February 2008
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CRYSTAL STRUCTURE OF MUTANT M211S/R215L OF CARBOXYLESTERASE EST2 COMPLEXED WITH HEXADECANESULFONATE
Overview
The reaction mechanism of the esterase 2 (EST2) from Alicyclobacillus acidocaldarius was studied at the kinetic and structural level to shed light on the mechanism of activity and substrate specificity increase previously observed in its double mutant M211S/R215L. In particular, the values of kinetic constants (k1, k(-1), k2, and k3) along with activation energies (E1, E(-1), E2, and E3) were measured for wild type and mutant enzyme. The previously suggested substrate-induced switch in the reaction mechanism from kcat=k3 with a short acyl chain substrate (p-nitrophenyl hexanoate) to kcat=k2 with a long acyl chain substrate (p-nitrophenyl dodecanoate) was validated. The inhibition afforded by an irreversible inhibitor (1-hexadecanesulfonyl chloride), structurally related to p-nitrophenyl dodecanoate, was studied by kinetic analysis. Moreover the three-dimensional structure of the double mutant bound to this inhibitor was determined, providing essential information on the enzyme mechanism. In fact, structural analysis explained the observed substrate-induced switch because of an inversion in the binding mode of the long acyl chain derivatives with respect to the acyl- and alcohol-binding sites.
About this Structure
1QZ3 is a Single protein structure of sequence from Alicyclobacillus acidocaldarius with as ligand. Active as Carboxylesterase, with EC number 3.1.1.1 Full crystallographic information is available from OCA.
Reference
A substrate-induced switch in the reaction mechanism of a thermophilic esterase: kinetic evidences and structural basis., De Simone G, Mandrich L, Menchise V, Giordano V, Febbraio F, Rossi M, Pedone C, Manco G, J Biol Chem. 2004 Feb 20;279(8):6815-23. Epub 2003 Nov 15. PMID:14617621
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