de.mpg.escidoc.pubman.appbase.FacesBean
Deutsch
 
Hilfe Wegweiser Impressum Kontakt Einloggen
  DetailsucheBrowse

Datensatz

DATENSATZ AKTIONENEXPORT

Freigegeben

Zeitschriftenartikel

Crystal structure of the plant PPC decarboxylase AtHAL3a complexed with an ene-thiol reaction intermediate

MPG-Autoren
http://pubman.mpdl.mpg.de/cone/persons/resource/persons77763

Bieseler,  B.
Huber, Robert / Structure Research, Max Planck Institute of Biochemistry, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons78142

Huber,  R.
Huber, Robert / Structure Research, Max Planck Institute of Biochemistry, Max Planck Society;

Externe Ressourcen
Es sind keine Externen Ressourcen verfügbar
Volltexte (frei zugänglich)
Es sind keine frei zugänglichen Volltexte verfügbar
Ergänzendes Material (frei zugänglich)
Es sind keine frei zugänglichen Ergänzenden Materialien verfügbar
Zitation

Steinbacher, S., Hernandez-Acosta, P., Bieseler, B., Blaesse, M., Huber, R., Culianez-Macia, F. A., et al. (2003). Crystal structure of the plant PPC decarboxylase AtHAL3a complexed with an ene-thiol reaction intermediate. Journal of Molecular Biology, 327(1), 193-202.


Zitierlink: http://hdl.handle.net/11858/00-001M-0000-0010-6C6B-1
Zusammenfassung
The Arabidopsis thaliana protein AtHAL3a decarboxylates 4'- phospho-pantothenoylcysteine to 4'-phosphopantetheine, a step in coenzyme A biosynthesis. Surprisingly, this decarboxylation reaction is carried out as an FMN-dependent redox reaction. In the first half-reaction, the side-chain of the cysteine residue of 4'-phosphopantothenoylcysteine is oxidised and the thioaldehyde intermediate decarboxylates spontaneously to the 4 -phosphopantothenoyl-aminoethenethiol intermediate. In the second half-reaction this compound is reduced to 4 - phosphopantetheine and the FMNH2 cofactor is re-oxidised. The active site mutant C175S is unable to perform this reductive half-reaction. Here, we present the crystal structure of the AtHAL3a mutant C175S in complex with the reaction intermediate pantothenoyl-aminoethenethiol and FMNH2. The geometry of binding suggests that reduction of the C-alpha=C-beta double bond of the intermediate can be performed by direct hydride- transfer from N5 of FMNH2 to C-beta of the aminoethenethiol- moiety supported by a protonation of C-alpha by Cys175. The binding mode of the substrate is very similar to that previously observed for a pentapeptide to the homologous enzyme EpiD that introduces the aminoethenethiol-moiety as final reaction product at the C terminus of peptidyl-cysteine residues. This finding further supports our view that these homologous enzymes form a protein family of homo-oligomeric flavin-containing cysteine decarboxylases, which we have termed HFCD family. (C) 2003 Elsevier Science Ltd. All rights reserved.