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

The biochemical and genetic search for a be, complex in Rhodothermus marinus was always fruitless; however, a functional equivalent, i.e. having quinol:cytochrome c oxidoreductase activity was characterized. Now, with the sequencing of R. marinus genome, it was possible to assign the N-terminal sequences of several proteins of this complex to its coding genes. The alternative complex III from R. marinus has the same genomic organization of the so-called MFIcc complexes, proposed to be oxidoreductases of the respiratory and photosynthetic electron transfer chains. In this report, we establish undoubtedly the existence of an alternative complex III, a functional substitute of the he, complex, by its identification at both the biochemical and genomic level. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.