1mo2
From Proteopedia
(New page: 200px<br /><applet load="1mo2" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mo2, resolution 3.00Å" /> '''Thioesterase Domain ...) |
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| - | [[Image:1mo2.jpg|left|200px]]<br /><applet load="1mo2" size=" | + | [[Image:1mo2.jpg|left|200px]]<br /><applet load="1mo2" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1mo2, resolution 3.00Å" /> | caption="1mo2, resolution 3.00Å" /> | ||
'''Thioesterase Domain from 6-Deoxyerythronolide Synthase (DEBS TE), pH 8.5'''<br /> | '''Thioesterase Domain from 6-Deoxyerythronolide Synthase (DEBS TE), pH 8.5'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Modular polyketide synthases (PKSs) synthesize the polyketide cores of | + | Modular polyketide synthases (PKSs) synthesize the polyketide cores of pharmacologically important natural products such as erythromycin and picromycin. Understanding PKSs at high resolution could present new opportunities for chemoenzymatic synthesis of complex molecules. The crystal structures of macrocycle-forming thioesterase (TE) domains from the picromycin synthase (PICS) and 6-deoxyerythronolide B synthase (DEBS) were determined to 1.8-3.0 A with an R(crys) of 19.2-24.4%, including three structures of PICS TE (crystallized at pH 7.6, 8.0, and 8.4) and a second crystal form of DEBS TE. As predicted by the previous work on DEBS TE [Tsai, S. C., et al. (2001) Proc. Natl. Acad. Sci. U.S.A. 98, 14808-14813], PICS TE contains an open substrate channel and a hydrophobic dimer interface. Notwithstanding their similarity, the dimer interfaces and substrate channels of DEBS TE and PICS TE reveal key differences. The structural basis for the divergent substrate specificities of DEBS TE and PICS TE is analyzed. The size of the substrate channel increases with increasing pH, presumably due to electrostatic repulsion in the channel at elevated pH. Together, these structures support previous predictions that macrocycle-forming thioesterases from PKSs share the same protein fold, an open substrate channel, a similar catalytic mechanism, and a hydrophobic dimer interface. They also provide a basis for the design of enzymes capable of catalyzing regioselective macrocyclization of natural or synthetic substrates. A series of high-resolution snapshots of a protein channel at different pHs is presented alongside analysis of channel residues, which could help in the redesign of the protein channel architecture. |
==About this Structure== | ==About this Structure== | ||
| - | 1MO2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharopolyspora_erythraea Saccharopolyspora erythraea]. Active as [http://en.wikipedia.org/wiki/Erythronolide_synthase Erythronolide synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.94 2.3.1.94] Full crystallographic information is available from [http:// | + | 1MO2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharopolyspora_erythraea Saccharopolyspora erythraea]. Active as [http://en.wikipedia.org/wiki/Erythronolide_synthase Erythronolide synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.94 2.3.1.94] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MO2 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Saccharopolyspora erythraea]] | [[Category: Saccharopolyspora erythraea]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Cane, D | + | [[Category: Cane, D E.]] |
[[Category: Khosla, C.]] | [[Category: Khosla, C.]] | ||
[[Category: Lu, H.]] | [[Category: Lu, H.]] | ||
| - | [[Category: Stroud, R | + | [[Category: Stroud, R M.]] |
| - | [[Category: Tsai, S | + | [[Category: Tsai, S C.]] |
[[Category: 6-deoxyerythronolide]] | [[Category: 6-deoxyerythronolide]] | ||
[[Category: alpha beta hydrolase]] | [[Category: alpha beta hydrolase]] | ||
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[[Category: thioesterase]] | [[Category: thioesterase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:57:11 2008'' |
Revision as of 11:57, 21 February 2008
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Thioesterase Domain from 6-Deoxyerythronolide Synthase (DEBS TE), pH 8.5
Overview
Modular polyketide synthases (PKSs) synthesize the polyketide cores of pharmacologically important natural products such as erythromycin and picromycin. Understanding PKSs at high resolution could present new opportunities for chemoenzymatic synthesis of complex molecules. The crystal structures of macrocycle-forming thioesterase (TE) domains from the picromycin synthase (PICS) and 6-deoxyerythronolide B synthase (DEBS) were determined to 1.8-3.0 A with an R(crys) of 19.2-24.4%, including three structures of PICS TE (crystallized at pH 7.6, 8.0, and 8.4) and a second crystal form of DEBS TE. As predicted by the previous work on DEBS TE [Tsai, S. C., et al. (2001) Proc. Natl. Acad. Sci. U.S.A. 98, 14808-14813], PICS TE contains an open substrate channel and a hydrophobic dimer interface. Notwithstanding their similarity, the dimer interfaces and substrate channels of DEBS TE and PICS TE reveal key differences. The structural basis for the divergent substrate specificities of DEBS TE and PICS TE is analyzed. The size of the substrate channel increases with increasing pH, presumably due to electrostatic repulsion in the channel at elevated pH. Together, these structures support previous predictions that macrocycle-forming thioesterases from PKSs share the same protein fold, an open substrate channel, a similar catalytic mechanism, and a hydrophobic dimer interface. They also provide a basis for the design of enzymes capable of catalyzing regioselective macrocyclization of natural or synthetic substrates. A series of high-resolution snapshots of a protein channel at different pHs is presented alongside analysis of channel residues, which could help in the redesign of the protein channel architecture.
About this Structure
1MO2 is a Single protein structure of sequence from Saccharopolyspora erythraea. Active as Erythronolide synthase, with EC number 2.3.1.94 Full crystallographic information is available from OCA.
Reference
Insights into channel architecture and substrate specificity from crystal structures of two macrocycle-forming thioesterases of modular polyketide synthases., Tsai SC, Lu H, Cane DE, Khosla C, Stroud RM, Biochemistry. 2002 Oct 22;41(42):12598-606. PMID:12379102
Page seeded by OCA on Thu Feb 21 13:57:11 2008
Categories: Erythronolide synthase | Saccharopolyspora erythraea | Single protein | Cane, D E. | Khosla, C. | Lu, H. | Stroud, R M. | Tsai, S C. | 6-deoxyerythronolide | Alpha beta hydrolase | Erythromycin | Open substrate channel | Picromycin | Pikromycin | Pks | Polyketide synthase | Te | Thioesterase
