1dje: Difference between revisions
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[[Image:1dje.gif|left|200px]] | [[Image:1dje.gif|left|200px]] | ||
'''CRYSTAL STRUCTURE OF THE PLP-BOUND FORM OF 8-AMINO-7-OXONANOATE SYNTHASE''' | {{Structure | ||
|PDB= 1dje |SIZE=350|CAPTION= <scene name='initialview01'>1dje</scene>, resolution 1.71Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> and <scene name='pdbligand=PLP:PYRIDOXAL-5'-PHOSPHATE'>PLP</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/8-amino-7-oxononanoate_synthase 8-amino-7-oxononanoate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.47 2.3.1.47] | |||
|GENE= | |||
}} | |||
'''CRYSTAL STRUCTURE OF THE PLP-BOUND FORM OF 8-AMINO-7-OXONANOATE SYNTHASE''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1DJE is a [ | 1DJE is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DJE OCA]. | ||
==Reference== | ==Reference== | ||
Mechanism of 8-amino-7-oxononanoate synthase: spectroscopic, kinetic, and crystallographic studies., Webster SP, Alexeev D, Campopiano DJ, Watt RM, Alexeeva M, Sawyer L, Baxter RL, Biochemistry. 2000 Jan 25;39(3):516-28. PMID:[http:// | Mechanism of 8-amino-7-oxononanoate synthase: spectroscopic, kinetic, and crystallographic studies., Webster SP, Alexeev D, Campopiano DJ, Watt RM, Alexeeva M, Sawyer L, Baxter RL, Biochemistry. 2000 Jan 25;39(3):516-28. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10642176 10642176] | ||
[[Category: 8-amino-7-oxononanoate synthase]] | [[Category: 8-amino-7-oxononanoate synthase]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 10:39:24 2008'' | ||
Revision as of 11:39, 20 March 2008
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| , resolution 1.71Å | |||||||
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| Ligands: | and | ||||||
| Activity: | 8-amino-7-oxononanoate synthase, with EC number 2.3.1.47 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF THE PLP-BOUND FORM OF 8-AMINO-7-OXONANOATE SYNTHASE
OverviewOverview
8-Amino-7-oxononanoate synthase (also known as 7-keto-8-aminopelargonate synthase, EC 2.3.1.47) is a pyridoxal 5'-phosphate-dependent enzyme which catalyzes the decarboxylative condensation of L-alanine with pimeloyl-CoA in a stereospecific manner to form 8(S)-amino-7-oxononanoate. This is the first committed step in biotin biosynthesis. The mechanism of Escherichia coli AONS has been investigated by spectroscopic, kinetic, and crystallographic techniques. The X-ray structure of the holoenzyme has been refined at a resolution of 1.7 A (R = 18.6%, R(free) = 21. 2%) and shows that the plane of the imine bond of the internal aldimine deviates from the pyridine plane. The structure of the enzyme-product external aldimine complex has been refined at a resolution of 2.0 A (R = 21.2%, R(free) = 27.8%) and shows a rotation of the pyridine ring with respect to that in the internal aldimine, together with a significant conformational change of the C-terminal domain and subtle rearrangement of the active site hydrogen bonding. The first step in the reaction, L-alanine external aldimine formation, is rapid (k(1) = 2 x 10(4) M(-)(1) s(-)(1)). Formation of an external aldimine with D-alanine, which is not a substrate, is significantly slower (k(1) = 125 M(-)(1) s(-)(1)). Binding of D-alanine to AONS is enhanced approximately 2-fold in the presence of pimeloyl-CoA. Significant substrate quinonoid formation only occurs upon addition of pimeloyl-CoA to the preformed L-alanine external aldimine complex and is preceded by a distinct lag phase ( approximately 30 ms) which suggests that binding of the pimeloyl-CoA causes a conformational transition of the enzyme external aldimine complex. This transition, which is inferred by modeling to require a rotation around the Calpha-N bond of the external aldimine complex, promotes abstraction of the Calpha proton by Lys236. These results have been combined to form a detailed mechanistic pathway for AONS catalysis which may be applied to the other members of the alpha-oxoamine synthase subfamily.
About this StructureAbout this Structure
1DJE is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Mechanism of 8-amino-7-oxononanoate synthase: spectroscopic, kinetic, and crystallographic studies., Webster SP, Alexeev D, Campopiano DJ, Watt RM, Alexeeva M, Sawyer L, Baxter RL, Biochemistry. 2000 Jan 25;39(3):516-28. PMID:10642176
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