SCAN: Deciphering energy metabolism in the earliest life forms: the dissimilatory reduction of sulfur compounds

SCAN Seminar

Title: Deciphering energy metabolism in the earliest life forms: the dissimilatory reduction of sulfur compounds

Speaker: Inês Cardoso Pereira

Lab: Bacterial Energy Metabolism

 

Abstract

The dissimilatory reduction of sulfur compounds is one of the most ancient forms of energy metabolism on Earth, which was present in early organisms before the divergence of the Archaea and Bacteria domains. Sulfate reduction in particular was traced back to the early Archaean, and its link to the atmospheric oxygen concentration make it a key process for studying the evolution of the Earth surface oxidation over geological time. Sulfate reduction is a process of global importance due to its role in the biogeochemical cycling of sulfur and its major contribution to the sulfur and carbon cycles in anaerobic environments. It has also very important environmental and economical consequences.
In the Bacterial Energy Metabolism laboratory we are interested in energy metabolism of anaerobic organisms, and have focused in elucidating the respiratory chain of sulfate-reducing prokaryotes (SRP). The sites of energy conservation in these organisms have not been clearly established, even though a chemiosmotic mechanism is known to be present. Our team has contributed to elucidating this process by characterizing several new proteins involved in the process, including two conserved membrane complexes in SRP, QmoABC and DsrMKJOP, involved in electron transfer to the terminal reductases. In this talk I will describe recent advances in this field from our laboratory.