706 / 2019-05-02 20:33:37

Arabidopsis proteins ID1/ID2 are essential for the chloroplastic iron-sulfur cluster biosynthesis

chloroplastic Fe-S cluster,,ID1/ID2,,photosynthetic electron transport,chloroplast development

全体主题 > Photosynthesis

As one of the most ancient and unquestionable natural prosthetic group, iron-sulfur clusters are highly demanded in all living organisms, as reflected by their involvement in nearly all fundamental metabolic processes, such as electron transport, enzyme catalysis, regulation of gene expression and sensing of environmental stimuli. To date, a basic framework of this assembly process of Fe-S clusters has been presented: the iron acquisition and sulfur formation, assembly of iron and sulfur into a cluster, and cluster insertion into client proteins. However, the source of Fe is still under dispute. We demonstrated that a novel component of chloroplastic Fe-S cluster assembly system, ID1/ID2 is critical for chloroplastic Fe-S proteins maturation and plant viability. Inactivation of ID1 and ID2 led to iron overload in leaves and impaired chloroplastic Fe-S proteins accumulation, along with the impairment of photosynthetic electron transport and chloroplast development. Further biochemical analysis revealed the iron-binding properties of ID1 and the ability to supply iron for transient Fe-S clusters assembly in vitro. These results suggest that ID1 and ID2 may act as iron donors for chloroplastic Fe-S cluster assembly.