1f91: Difference between revisions

From Proteopedia
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
[[Image:1f91.gif|left|200px]]
{{Seed}}
[[Image:1f91.png|left|200px]]


<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1f91|  PDB=1f91  |  SCENE=  }}  
{{STRUCTURE_1f91|  PDB=1f91  |  SCENE=  }}  


'''BETA-KETOACYL-[ACYL-CARRIER-PROTEIN] SYNTHASE I IN COMPLEX WITH C10 FATTY ACID SUBSTRATE'''
===BETA-KETOACYL-[ACYL-CARRIER-PROTEIN] SYNTHASE I IN COMPLEX WITH C10 FATTY ACID SUBSTRATE===




==Overview==
<!--  
BACKGROUND: beta-ketoacyl-acyl carrier protein synthase (KAS) I is vital for the construction of the unsaturated fatty acid carbon skeletons characterizing E. coli membrane lipids. The new carbon-carbon bonds are created by KAS I in a Claisen condensation performed in a three-step enzymatic reaction. KAS I belongs to the thiolase fold enzymes, of which structures are known for five other enzymes. RESULTS: Structures of the catalytic Cys-Ser KAS I mutant with covalently bound C10 and C12 acyl substrates have been determined to 2.40 and 1.85 A resolution, respectively. The KAS I dimer is not changed by the formation of the complexes but reveals an asymmetric binding of the two substrates bound to the dimer. A detailed model is proposed for the catalysis of KAS I. Of the two histidines required for decarboxylation, one donates a hydrogen bond to the malonyl thioester oxo group, and the other abstracts a proton from the leaving group. CONCLUSIONS: The same mechanism is proposed for KAS II, which also has a Cys-His-His active site triad. Comparison to the active site architectures of other thiolase fold enzymes carrying out a decarboxylation step suggests that chalcone synthase and KAS III with Cys-His-Asn triads use another mechanism in which both the histidine and the asparagine interact with the thioester oxo group. The acyl binding pockets of KAS I and KAS II are so similar that they alone cannot provide the basis for their differences in substrate specificity.
The line below this paragraph, {{ABSTRACT_PUBMED_11286890}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 11286890 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_11286890}}


==About this Structure==
==About this Structure==
Line 30: Line 34:
[[Category: Dimer]]
[[Category: Dimer]]
[[Category: Thiolase fold family]]
[[Category: Thiolase fold family]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 16:02:57 2008''
 
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 02:53:34 2008''

Revision as of 02:53, 1 July 2008

File:1f91.png

Template:STRUCTURE 1f91

BETA-KETOACYL-[ACYL-CARRIER-PROTEIN] SYNTHASE I IN COMPLEX WITH C10 FATTY ACID SUBSTRATEBETA-KETOACYL-[ACYL-CARRIER-PROTEIN] SYNTHASE I IN COMPLEX WITH C10 FATTY ACID SUBSTRATE

Template:ABSTRACT PUBMED 11286890

About this StructureAbout this Structure

1F91 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

Structures of beta-ketoacyl-acyl carrier protein synthase I complexed with fatty acids elucidate its catalytic machinery., Olsen JG, Kadziola A, von Wettstein-Knowles P, Siggaard-Andersen M, Larsen S, Structure. 2001 Mar 7;9(3):233-43. PMID:11286890

Page seeded by OCA on Tue Jul 1 02:53:34 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA