1b6t: Difference between revisions

Revision as of 11:08, 2 May 2008

PHOSPHOPANTETHEINE ADENYLYLTRANSFERASE IN COMPLEX WITH 3'-DEPHOSPHO-COA FROM ESCHERICHIA COLI

OverviewOverview

Phosphopantetheine adenylyltransferase (PPAT) is an essential enzyme in bacteria that catalyses a rate-limiting step in coenzyme A (CoA) biosynthesis, by transferring an adenylyl group from ATP to 4'-phosphopantetheine, yielding dephospho-CoA (dPCoA). Each phosphopantetheine adenylyltransferase (PPAT) subunit displays a dinucleotide-binding fold that is structurally similar to that in class I aminoacyl-tRNA synthetases. Superposition of bound adenylyl moieties from dPCoA in PPAT and ATP in aminoacyl-tRNA synthetases suggests nucleophilic attack by the 4'-phosphopantetheine on the alpha-phosphate of ATP. The proposed catalytic mechanism implicates transition state stabilization by PPAT without involving functional groups of the enzyme in a chemical sense in the reaction. The crystal structure of the enzyme from Escherichia coli in complex with dPCoA shows that binding at one site causes a vice-like movement of active site residues lining the active site surface. The mode of enzyme product formation is highly concerted, with only one trimer of the PPAT hexamer showing evidence of dPCoA binding. The homologous active site attachment of ATP and the structural distribution of predicted sequence-binding motifs in PPAT classify the enzyme as belonging to the nucleotidyltransferase superfamily.

About this StructureAbout this Structure

1B6T is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

The crystal structure of a novel bacterial adenylyltransferase reveals half of sites reactivity., Izard T, Geerlof A, EMBO J. 1999 Apr 15;18(8):2021-30. PMID:10205156 Page seeded by OCA on Fri May 2 11:08:35 2008

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OCA

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 [[Image:1b6t.gif|left|200px]]
- {{Structure
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+The line below this paragraph, containing "STRUCTURE_1b6t", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=COD:DEPHOSPHO+COENZYME+A'>COD</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Pantetheine-phosphate_adenylyltransferase Pantetheine-phosphate adenylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.3 2.7.7.3] </span>
+or leave the SCENE parameter empty for the default display.
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-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1b6t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1b6t OCA], [http://www.ebi.ac.uk/pdbsum/1b6t PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1b6t RCSB]</span>
-}}
 '''PHOSPHOPANTETHEINE ADENYLYLTRANSFERASE IN COMPLEX WITH 3'-DEPHOSPHO-COA FROM ESCHERICHIA COLI'''
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 [[Category: Single protein]]
 [[Category: Izard, T.]]
-[[Category: coenzyme a biosynthesis]]
+[[Category: Coenzyme a biosynthesis]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 11:08:35 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 18:54:46 2008''