1evq: Difference between revisions
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New page: left|200px<br /><applet load="1evq" size="450" color="white" frame="true" align="right" spinBox="true" caption="1evq, resolution 2.6Å" /> '''THE CRYSTAL STRUCTURE... |
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[[Image:1evq.gif|left|200px]]<br /><applet load="1evq" size=" | [[Image:1evq.gif|left|200px]]<br /><applet load="1evq" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1evq, resolution 2.6Å" /> | caption="1evq, resolution 2.6Å" /> | ||
'''THE CRYSTAL STRUCTURE OF THE THERMOPHILIC CARBOXYLESTERASE EST2 FROM ALICYCLOBACILLUS ACIDOCALDARIUS'''<br /> | '''THE CRYSTAL STRUCTURE OF THE THERMOPHILIC CARBOXYLESTERASE EST2 FROM ALICYCLOBACILLUS ACIDOCALDARIUS'''<br /> | ||
==Overview== | ==Overview== | ||
EST2 is a novel thermophilic carboxylesterase, isolated and cloned from | EST2 is a novel thermophilic carboxylesterase, isolated and cloned from Alicyclobacillus (formerly Bacillus) acidocaldarius, which optimally hydrolyses esters with acyl chain lengths of six to eight carbon atoms at 70 degrees C. On the basis of the amino acid sequence homology, it has been classified as a member of the mammalian hormone-sensitive lipase (HSL) subfamily.The crystal structure of EST2, complexed with a sulphonyl derivative, has been determined at 2.6 A resolution by a multiple wavelength anomalous diffraction experiment on a seleno-methionine derivative. EST2 presents a canonical alpha/beta hydrolase core, shielded at the C-terminal side by a cap region built up of five helices. It contains the lipase-like catalytic triad, Ser155, His282 and Asp252, whereby the nucleophile is covalently modified. This allows an unambiguous view of the putative active site of EST2, detecting the oxyanion hole, in whose formation the amino acid sequence motif His81-Gly82-Gly83-Gly84 is involved, and the hydrophobic binding pocket for the acyl chain. The structural model here reported provides the first example of a transition state analogue of an esterase/lipase belonging to the HSL group, thus affording useful information for the design of medical inhibitors. Moreover, as the first X-ray structure of a thermophilic carboxylesterase, the comparison with its mesophilic homologue, the Brefeldin A esterase (BFAE) from Bacillus subtilis, allows the identification of putative determinants of thermal stability. | ||
==About this Structure== | ==About this Structure== | ||
1EVQ 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 EPE and TRS as [http://en.wikipedia.org/wiki/ligands ligands]. 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:// | 1EVQ 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=EPE:'>EPE</scene> and <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. 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=1EVQ 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: EPE]] | [[Category: EPE]] | ||
[[Category: TRS]] | [[Category: TRS]] | ||
[[Category: alpha/beta hydrolase fold]] | [[Category: alpha/beta hydrolase fold]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:32:00 2008'' | ||