1isk: Difference between revisions
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==Overview== | ==Overview== | ||
The three-dimensional structure of the enzyme 3-oxo-delta5-steroid, isomerase (E.C. 5.3.3.1), a 28-kilodalton symmetrical dimer, was solved by, multidimensional heteronuclear magnetic resonance spectroscopy. The two, independently folded monomers pack together by means of extensive, hydrophobic and electrostatic interactions. Each monomer comprises three, alpha helices and a six-strand mixed beta-pleated sheet arranged to form a, deep hydrophobic cavity. Catalytically important residues Tyr14 (general, acid) and Asp38 (general base) are located near the bottom of the cavity, and positioned as expected from mechanistic hypotheses. An unexpected acid, group (Asp99) is also located in the active site adjacent to Tyr14, and, kinetic and binding studies of the Asp99 to Ala mutant demonstrate . | The three-dimensional structure of the enzyme 3-oxo-delta5-steroid, isomerase (E.C. 5.3.3.1), a 28-kilodalton symmetrical dimer, was solved by, multidimensional heteronuclear magnetic resonance spectroscopy. The two, independently folded monomers pack together by means of extensive, hydrophobic and electrostatic interactions. Each monomer comprises three, alpha helices and a six-strand mixed beta-pleated sheet arranged to form a, deep hydrophobic cavity. Catalytically important residues Tyr14 (general, acid) and Asp38 (general base) are located near the bottom of the cavity, and positioned as expected from mechanistic hypotheses. An unexpected acid, group (Asp99) is also located in the active site adjacent to Tyr14, and, kinetic and binding studies of the Asp99 to Ala mutant demonstrate that, Asp99 contributes to catalysis by stabilizing the intermediate. | ||
==About this Structure== | ==About this Structure== | ||
1ISK is a | 1ISK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Comamonas_testosteroni Comamonas testosteroni]. Active as [http://en.wikipedia.org/wiki/Steroid_Delta-isomerase Steroid Delta-isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.3.1 5.3.3.1] Structure known Active Sites: SIA and SIB. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1ISK OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: ksi]] | [[Category: ksi]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 12:54:23 2007'' | ||
