SCAN:The alternative complex III from Rhodothermus marinus - a prototype of a new family of quinol:electron acceptor oxidoreductases

Abstract

Quinol:cytochrome c oxidoreductases (complex III) are membrane bound complexes involved in the electron transfer respiratory chain of mitochondria and several prokaryotes. These complexes are frequently called cytochrome bc1 complexes since until now they were known as having a cytochrome b, a cytochrome c and a Rieske centre.

The biochemical, spectroscopic and genetic search for a bc1 complex from the thermohalophilic bacterium Rhodothermus marinus was always fruitless. This work reports the purification and characterization of a functional equivalent complex isolated from its membranes. This alternative complex III is a six subunit complex; three of the subunits are peripheral proteins (a monohemic and a pentahemic cytochromes c, and a large protein predicted to have one binding site for a [3Fe-4S]1+/0 and three for [4Fe4S]2+/1+ iron sulphur centres). The other three subunits are transmembrane proteins. This is the first report of such a respiratory complex which is predicted to be also present in the respiratory chain from several prokaryotes.

The interaction of this new complex III and the terminal oxygen reductase was addressed and it was observed that these complexes establish a functional supercomplex.

Short CV

2000-2005- Degree in Biochemistry by the Faculdade de Ciências da Universidade de Lisboa
2004-2005- Undergraduate training at the Metalloproteins and Bioenergetics Laboratory at Instituto de Tecnologia Química e Biológica under the supervision of Prof. Miguel Teixeira and Dra. Manuela Pereira.
Since January of 2006 - PhD fellowship by Fundação para a Ciência e Tecnologia, on the “Study of proteins with quinol oxidase activity” under the supervision of Prof. Miguel Teixeira and Dra. Manuela Pereira