Quinolinate synthase, an iron-sulfur enzyme in NAD biosynthesis - BIG - Chimie et Biologie des Métaux (CBM) Accéder directement au contenu
Article Dans Une Revue FEBS Letters Année : 2005

Quinolinate synthase, an iron-sulfur enzyme in NAD biosynthesis

Résumé

Nicotinamide adenine dinucleotide (NAD) plays a crucial role as a cofactor in numerous essential redox biological reactions. NAD derives from quinolinic acid which is synthesized in E. coli from L-aspartate and dihydroxyacetone phosphate (DHAP) as the result of the concerted action of two enzymes, L-aspartate oxidase (NadB) and quinolinate synthetase (NadA). We report here the characterization of NadA protein from E. coli. When anaerobically purified, the isolated soluble protein contains 3-3.5 iron and 3-3.5 sulfide/ polypeptide chain. Mössbauer spectra of the 57Fe-protein revealed that the majority of the iron is in the form of a (4Fe-4S)2+ cluster. An enzymatic assay for quinolinate synthetase activity was set up and allowed to demonstrate that the cluster is absolutely required for NadA activity. Exposure to air leads to degradation of the cluster and inactivate enzyme.
Fichier principal
Vignette du fichier
NadAFEBS2.pdf (111.21 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-00374522 , version 1 (08-04-2009)

Identifiants

Citer

Sandrine Ollagnier de Choudens, Laurent Loiseau, Yiannis Sanakis, Frédéric Barras, Marc Fontecave. Quinolinate synthase, an iron-sulfur enzyme in NAD biosynthesis. FEBS Letters, 2005, 579, pp.3737-3743. ⟨10.1016/j.febslet.2005.05.065⟩. ⟨hal-00374522⟩
249 Consultations
258 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More