The Zn center of the anaerobic ribonucleotide reductase from E. coli - Laboratoire de Chimie des Processus Biologiques Accéder directement au contenu
Article Dans Une Revue Journal of Biological Inorganic Chemistry Année : 2009

The Zn center of the anaerobic ribonucleotide reductase from E. coli

Résumé

Strict and facultative anaerobes depend on a class III ribonucleotide reductase for their growth. These enzymes are the sole cellular catalysts for de novo biosynthesis of the deoxyribonucleotides needed for DNA chain elongation and repair. In its active form, the class III ribonucleotide reductase from Escherichia coli contains a free radical located on the G681 residue which is essential for the activation of the ribonucleotide substrate toward its reduction. The 3D structure of the homologous enzyme from bacteriophage T4 has revealed the presence of a metal center bound to four conserved cysteine residues. In this report we identify the metal of the E. coli enzyme as Zn. We show that the presence of Zn in this site protects the protein from proteolysis and prevents the formation of disulfide bridges within it. Finally, we show with the fully Zn-loaded reductase that thioredoxin or small thiols are dispensable for the formation of the glycyl radical. However, they are necessary for obtaining high turnover numbers, suggesting that they intervene in radical transfer steps subsequent to the formation of the glycyl radical.

Dates et versions

hal-01157571 , version 1 (28-05-2015)

Identifiants

Citer

Florence Luttringer, Etienne Mulliez, Bernard Dublet, David Lemaire, Marc Fontecave. The Zn center of the anaerobic ribonucleotide reductase from E. coli. Journal of Biological Inorganic Chemistry, 2009, 14 (6), pp.923-933. ⟨10.1007/s00775-009-0505-9⟩. ⟨hal-01157571⟩
105 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More