2c7y
From Proteopedia
(New page: 200px<br /><applet load="2c7y" size="450" color="white" frame="true" align="right" spinBox="true" caption="2c7y, resolution 2.10Å" /> '''PLANT ENZYME'''<br /...) |
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| - | [[Image:2c7y.gif|left|200px]]<br /><applet load="2c7y" size=" | + | [[Image:2c7y.gif|left|200px]]<br /><applet load="2c7y" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2c7y, resolution 2.10Å" /> | caption="2c7y, resolution 2.10Å" /> | ||
'''PLANT ENZYME'''<br /> | '''PLANT ENZYME'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Crystal structures of peroxisomal Arabidopsis thaliana 3-ketoacyl-CoA | + | Crystal structures of peroxisomal Arabidopsis thaliana 3-ketoacyl-CoA thiolase (AtKAT), an enzyme of fatty acid beta-oxidation, are reported. The subunit, a typical thiolase, is a combination of two similar alpha/beta domains capped with a loop domain. The comparison of AtKAT with the Saccharomyces cerevisiae homologue (ScKAT) structure reveals a different placement of subunits within the functional dimers and that a polypeptide segment forming an extended loop around the open catalytic pocket of ScKAT converts to alpha-helix in AtKAT, and occludes the active site. A disulfide is formed between Cys192, on this helix, and Cys138, a catalytic residue. Access to Cys138 is determined by the structure of this polypeptide segment. AtKAT represents an oxidized, previously unknown inactive form, whilst ScKAT is the reduced and active enzyme. A high level of sequence conservation is observed, including Cys192, in eukaryotic peroxisomal, but not mitochondrial or prokaryotic KAT sequences, for this labile loop/helix segment. This indicates that KAT activity in peroxisomes is influenced by a disulfide/dithiol change linking fatty acid beta-oxidation with redox regulation. |
==About this Structure== | ==About this Structure== | ||
| - | 2C7Y is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Active as [http://en.wikipedia.org/wiki/Acetyl-CoA_C-acyltransferase Acetyl-CoA C-acyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.16 2.3.1.16] Full crystallographic information is available from [http:// | + | 2C7Y is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Active as [http://en.wikipedia.org/wiki/Acetyl-CoA_C-acyltransferase Acetyl-CoA C-acyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.16 2.3.1.16] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2C7Y OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Arabidopsis thaliana]] | [[Category: Arabidopsis thaliana]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Alphey, M | + | [[Category: Alphey, M S.]] |
| - | [[Category: Bryce, J | + | [[Category: Bryce, J H.]] |
[[Category: Germain, V.]] | [[Category: Germain, V.]] | ||
| - | [[Category: Hunter, W | + | [[Category: Hunter, W N.]] |
| - | [[Category: Leonard, G | + | [[Category: Leonard, G A.]] |
[[Category: Micossi, E.]] | [[Category: Micossi, E.]] | ||
| - | [[Category: Smith, S | + | [[Category: Smith, S M.]] |
[[Category: Sundaramoorthy, R.]] | [[Category: Sundaramoorthy, R.]] | ||
[[Category: 3-ketoacylcoa thiolase]] | [[Category: 3-ketoacylcoa thiolase]] | ||
| Line 29: | Line 29: | ||
[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:45:52 2008'' |
Revision as of 14:45, 21 February 2008
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PLANT ENZYME
Overview
Crystal structures of peroxisomal Arabidopsis thaliana 3-ketoacyl-CoA thiolase (AtKAT), an enzyme of fatty acid beta-oxidation, are reported. The subunit, a typical thiolase, is a combination of two similar alpha/beta domains capped with a loop domain. The comparison of AtKAT with the Saccharomyces cerevisiae homologue (ScKAT) structure reveals a different placement of subunits within the functional dimers and that a polypeptide segment forming an extended loop around the open catalytic pocket of ScKAT converts to alpha-helix in AtKAT, and occludes the active site. A disulfide is formed between Cys192, on this helix, and Cys138, a catalytic residue. Access to Cys138 is determined by the structure of this polypeptide segment. AtKAT represents an oxidized, previously unknown inactive form, whilst ScKAT is the reduced and active enzyme. A high level of sequence conservation is observed, including Cys192, in eukaryotic peroxisomal, but not mitochondrial or prokaryotic KAT sequences, for this labile loop/helix segment. This indicates that KAT activity in peroxisomes is influenced by a disulfide/dithiol change linking fatty acid beta-oxidation with redox regulation.
About this Structure
2C7Y is a Single protein structure of sequence from Arabidopsis thaliana. Active as Acetyl-CoA C-acyltransferase, with EC number 2.3.1.16 Full crystallographic information is available from OCA.
Reference
The crystal structure of a plant 3-ketoacyl-CoA thiolase reveals the potential for redox control of peroxisomal fatty acid beta-oxidation., Sundaramoorthy R, Micossi E, Alphey MS, Germain V, Bryce JH, Smith SM, Leonard GA, Hunter WN, J Mol Biol. 2006 Jun 2;359(2):347-57. Epub 2006 Mar 29. PMID:16630629
Page seeded by OCA on Thu Feb 21 16:45:52 2008
Categories: Acetyl-CoA C-acyltransferase | Arabidopsis thaliana | Single protein | Alphey, M S. | Bryce, J H. | Germain, V. | Hunter, W N. | Leonard, G A. | Micossi, E. | Smith, S M. | Sundaramoorthy, R. | 3-ketoacylcoa thiolase | Acyltransferase | Fatty acid metabolism | Lipid synthesis | Oxylipin synthesis | Transferase
