Mitochondrial Arabidopsis thaliana TRXo Isoforms Bind an Iron⁻Sulfur Cluster and Reduce NFU Proteins In Vitro.

ABSTRACT: In plants, the mitochondrial thioredoxin (TRX) system generally comprises only one or two isoforms belonging to the TRX h or o classes, being less well developed compared to the numerous isoforms found in chloroplasts. Unlike most other plant species, Arabidopsis thaliana possesses two TRXo isoforms whose physiological functions remain unclear. Here, we performed a structure⁻function analysis to unravel the respective properties of the duplicated TRXo1 and TRXo2 isoforms. Surprisingly, when expressed in Escherichia coli, both recombinant proteins existed in an apo-monomeric form and in a homodimeric iron⁻sulfur (Fe-S) cluster-bridged form. In TRXo2, the [4Fe-4S] cluster is likely ligated in by the usual catalytic cysteines present in the conserved Trp-Cys-Gly-Pro-Cys signatur

SUBMITTER: Zannini F 

PROVIDER: S-EPMC6210436 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature