1kez
From Proteopedia
(New page: 200px<br /><applet load="1kez" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kez, resolution 2.8Å" /> '''Crystal Structure of ...) |
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| - | [[Image:1kez.jpg|left|200px]]<br /><applet load="1kez" size=" | + | [[Image:1kez.jpg|left|200px]]<br /><applet load="1kez" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1kez, resolution 2.8Å" /> | caption="1kez, resolution 2.8Å" /> | ||
'''Crystal Structure of the Macrocycle-forming Thioesterase Domain of Erythromycin Polyketide Synthase (DEBS TE)'''<br /> | '''Crystal Structure of the Macrocycle-forming Thioesterase Domain of Erythromycin Polyketide Synthase (DEBS TE)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | As the first structural elucidation of a modular polyketide synthase (PKS) | + | As the first structural elucidation of a modular polyketide synthase (PKS) domain, the crystal structure of the macrocycle-forming thioesterase (TE) domain from the 6-deoxyerythronolide B synthase (DEBS) was solved by a combination of multiple isomorphous replacement and multiwavelength anomalous dispersion and refined to an R factor of 24.1% to 2.8-A resolution. Its overall tertiary architecture belongs to the alpha/beta-hydrolase family, with two unusual features unprecedented in this family: a hydrophobic leucine-rich dimer interface and a substrate channel that passes through the entire protein. The active site triad, comprised of Asp-169, His-259, and Ser-142, is located in the middle of the substrate channel, suggesting the passage of the substrate through the protein. Modeling indicates that the active site can accommodate and orient the 6-deoxyerythronolide B precursor uniquely, while at the same time shielding the active site from external water and catalyzing cyclization by macrolactone formation. The geometry and organization of functional groups explain the observed substrate specificity of this TE and offer strategies for engineering macrocycle biosynthesis. Docking of a homology model of the upstream acyl carrier protein (ACP6) against the TE suggests that the 2-fold axis of the TE dimer may also be the axis of symmetry that determines the arrangement of domains in the entire DEBS. Sequence conservation suggests that all TEs from modular polyketide synthases have a similar fold, dimer 2-fold axis, and substrate channel geometry. |
==About this Structure== | ==About this Structure== | ||
| - | 1KEZ 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:// | + | 1KEZ 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=1KEZ 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: Chen, J | + | [[Category: Chen, J C.H.]] |
| - | [[Category: Foster, P | + | [[Category: Foster, P G.]] |
[[Category: Gokhale, R.]] | [[Category: Gokhale, R.]] | ||
[[Category: Khosla, C.]] | [[Category: Khosla, C.]] | ||
[[Category: Krucinski, J.]] | [[Category: Krucinski, J.]] | ||
| - | [[Category: Miercke, L | + | [[Category: Miercke, L J.W.]] |
| - | [[Category: Stroud, R | + | [[Category: Stroud, R M.]] |
| - | [[Category: Tsai, S | + | [[Category: Tsai, S C.]] |
[[Category: 6-deb]] | [[Category: 6-deb]] | ||
[[Category: 6-deoxyerythronolide synthase]] | [[Category: 6-deoxyerythronolide synthase]] | ||
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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 13:33:23 2008'' |
Revision as of 11:33, 21 February 2008
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Crystal Structure of the Macrocycle-forming Thioesterase Domain of Erythromycin Polyketide Synthase (DEBS TE)
Overview
As the first structural elucidation of a modular polyketide synthase (PKS) domain, the crystal structure of the macrocycle-forming thioesterase (TE) domain from the 6-deoxyerythronolide B synthase (DEBS) was solved by a combination of multiple isomorphous replacement and multiwavelength anomalous dispersion and refined to an R factor of 24.1% to 2.8-A resolution. Its overall tertiary architecture belongs to the alpha/beta-hydrolase family, with two unusual features unprecedented in this family: a hydrophobic leucine-rich dimer interface and a substrate channel that passes through the entire protein. The active site triad, comprised of Asp-169, His-259, and Ser-142, is located in the middle of the substrate channel, suggesting the passage of the substrate through the protein. Modeling indicates that the active site can accommodate and orient the 6-deoxyerythronolide B precursor uniquely, while at the same time shielding the active site from external water and catalyzing cyclization by macrolactone formation. The geometry and organization of functional groups explain the observed substrate specificity of this TE and offer strategies for engineering macrocycle biosynthesis. Docking of a homology model of the upstream acyl carrier protein (ACP6) against the TE suggests that the 2-fold axis of the TE dimer may also be the axis of symmetry that determines the arrangement of domains in the entire DEBS. Sequence conservation suggests that all TEs from modular polyketide synthases have a similar fold, dimer 2-fold axis, and substrate channel geometry.
About this Structure
1KEZ 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
Crystal structure of the macrocycle-forming thioesterase domain of the erythromycin polyketide synthase: versatility from a unique substrate channel., Tsai SC, Miercke LJ, Krucinski J, Gokhale R, Chen JC, Foster PG, Cane DE, Khosla C, Stroud RM, Proc Natl Acad Sci U S A. 2001 Dec 18;98(26):14808-13. PMID:11752428
Page seeded by OCA on Thu Feb 21 13:33:23 2008
Categories: Erythronolide synthase | Saccharopolyspora erythraea | Single protein | Cane, D E. | Chen, J C.H. | Foster, P G. | Gokhale, R. | Khosla, C. | Krucinski, J. | Miercke, L J.W. | Stroud, R M. | Tsai, S C. | 6-deb | 6-deoxyerythronolide synthase | Alpha | Beta-hydrolase | Debs | Macrocycle | Modular polyketide synthase | Polyketide synthase | Te | Thioesterase
