II - How do we study.

In order to study electron transfer chains and their components we use different organisms and different biochemical and spectroscopic techniques .

• Organisms

We study prokaryotic organisms from the Bacteria and Archaea domains. Prokaryotes have the advantage of possessing electron transfer complexes composed only by the so-called minimal functional units and thus are optimal models for characterization and for mechanistic studies. On the other hand prokaryotes are very versatile and diverse organisms, thus increasing the diversity of sampling. This is a very important feature because if the organisms understudy are from closely related phylogenetic groups, the conclusions of the analyses are strongly biased, i.e. , an observation that could be of general relevance may in fact be the reflex of the phylogenetic relationship and be only important for a certain group of organisms. Thus, a good sampling has to ensure representativity, including different living conditions and phylogenetic characteristics.

The organisms currently under study in the group are the bacteria Rhodothermus marinus , Bradyrhizobium japonicum, Escherichia coli (K12 and O157:H7 strains) , Synechocystis sp . PCC6803 and sulfate-reducing bacteria from the Desulfovibrio genus, and the archaea Acidianus ambivalens, Archaeoglobus fulgidus and Nanoarchaebacterium.

• Methodologies

In our group we cover the whole process of studying an electron transfer complex, i.e., we start from growing the organisms in the lab or at the IBET fermentation plant, continue with the isolation and protein purification through different chromatographic steps and pursue with the biochemical and spectroscopic characterisation. For this, several facilities and a great number of equipment are available.