@article{mbs:/content/journal/micro/10.1099/mic.0.2006/000067-0, author = "Bruscella, Patrice and Appia-Ayme, Corinne and Levicán, Gloria and Ratouchniak, Jeanine and Jedlicki, Eugenia and Holmes, David S. and Bonnefoy, Violaine", title = "Differential expression of two bc1 complexes in the strict acidophilic chemolithoautotrophic bacterium Acidithiobacillus ferrooxidans suggests a model for their respective roles in iron or sulfur oxidation", journal= "Microbiology", year = "2007", volume = "153", number = "1", pages = "102-110", doi = "https://doi.org/10.1099/mic.0.2006/000067-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2006/000067-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "Three strains of the strict acidophilic chemolithoautotrophic Acidithiobacillus ferrooxidans, including the type strain ATCC 23270, contain a petIIABC gene cluster that encodes the three proteins, cytochrome c 1, cytochrome b and a Rieske protein, that constitute a bc 1 electron-transfer complex. RT-PCR and Northern blotting show that the petIIABC cluster is co-transcribed with cycA, encoding a cytochrome c belonging to the c 4 family, sdrA, encoding a putative short-chain dehydrogenase, and hip, encoding a high potential iron–sulfur protein, suggesting that the six genes constitute an operon, termed the petII operon. Previous results indicated that A. ferrooxidans contains a second pet operon, termed the petI operon, which contains a gene cluster that is similarly organized except that it lacks hip. Real-time PCR and Northern blot experiments demonstrate that petI is transcribed mainly in cells grown in medium containing iron, whereas petII is transcribed in cells grown in media containing sulfur or iron. Primer extension experiments revealed possible transcription initiation sites for the petI and petII operons. A model is presented in which petI is proposed to encode the bc 1 complex, functioning in the uphill flow of electrons from iron to NAD(P), whereas petII is suggested to be involved in electron transfer from sulfur (or formate) to oxygen (or ferric iron). A. ferrooxidans is the only organism, to date, to exhibit two functional bc 1 complexes.", }