Iron-sulfphur (Fe-S) proteins play several key biological roles (respiration, photosynthesis, electron transfer, etc.). Several multi-protein complexes responsible for the correct assembly of iron and sulfphur atoms within these proteins have been identified in both bacteria and higher organisms.

Researchers at our laboratory partnered by the team directed by Professor Frédéric Barras (the bacterial microbiology research team at the CNRS unit in Marseille, UPR-CNRS 9043), has revealed a novel iron-sulfphur protein, ErpA, which belongs to the family of iron-sulfphur proteins referred to as "type-A scaffolds" and which play a key role in the Fe-S cluster assembly process.

The important finding of this research resides on the fact that the product of the erpA gene is essential for both aerobic and anaerobic respiratory metabolism in the Escherichia coli bacterium. Specifically, it plays a role in the isoprenoid biosynthetic pathway probably by assisting metal cluster assembly in the GcpE protein, which biosynthesizes isopentenyl-diphosphate. ErpA is therefore the first type-A Fe-S protein to be identified as playing an essential role in cell metabolism in Escherichia coli. These results illustrate, once again, the importance of iron-sulfphur cluster biosynthesis within cells.