2c7z: Difference between revisions
New page: left|200px<br /><applet load="2c7z" size="450" color="white" frame="true" align="right" spinBox="true" caption="2c7z, resolution 2.37Å" /> '''PLANT ENZYME CRYSTAL... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:2c7z.gif|left|200px]]<br /><applet load="2c7z" size=" | [[Image:2c7z.gif|left|200px]]<br /><applet load="2c7z" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2c7z, resolution 2.37Å" /> | caption="2c7z, resolution 2.37Å" /> | ||
'''PLANT ENZYME CRYSTAL FORM II'''<br /> | '''PLANT ENZYME CRYSTAL FORM II'''<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== | ||
2C7Z 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:// | 2C7Z 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=2C7Z OCA]. | ||
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Arabidopsis thaliana]] | [[Category: Arabidopsis thaliana]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Alphey, M | [[Category: Alphey, M S.]] | ||
[[Category: Hunter, W | [[Category: Hunter, W N.]] | ||
[[Category: Leonard, G | [[Category: Leonard, G A.]] | ||
[[Category: Micossi, E.]] | [[Category: Micossi, E.]] | ||
[[Category: Sundaramoorthy, R.]] | [[Category: Sundaramoorthy, R.]] | ||
| Line 26: | Line 26: | ||
[[Category: transferase]] | [[Category: transferase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:45:56 2008'' | ||
Revision as of 17:45, 21 February 2008
|
PLANT ENZYME CRYSTAL FORM II
OverviewOverview
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 StructureAbout this Structure
2C7Z 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.
ReferenceReference
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 16:45:56 2008