RT Journal Article SR Electronic(1) A1 Bardischewsky, Frank A1 Fischer, Jörg A1 Höller, Bettina A1 Friedrich, Cornelius G.YR 2006 T1 SoxV transfers electrons to the periplasm of Paracoccus pantotrophus – an essential reaction for chemotrophic sulfur oxidation JF Microbiology, VO 152 IS 2 SP 465 OP 472 DO https://doi.org/10.1099/mic.0.28523-0 PB Microbiology Society, SN 1465-2080, AB The soxVW genes are located upstream of the sox gene cluster encoding the sulfur-oxidizing ability of Paracoccus pantotrophus. SoxV is highly homologous to CcdA, which is involved in cytochrome c maturation of P. pantotrophus. SoxV was shown to function in reduction of the periplasmic SoxW, which shows a CysXaaXaaCys motif characteristic for thioredoxins. From strain GBΩV, which carries an Ω-kanamycin-resistance-encoding interposon in soxV, and complementation analysis it was evident that SoxV but not the periplasmic SoxW was essential for lithoautotrophic growth of P. pantotrophus with thiosulfate. However, the thiosulfate-oxidizing activities of cell extracts from the wild-type and from strain GBΩV were similar, demonstrating that the low thiosulfate-oxidizing activity of strain GBΩV in vivo was not due to a defect in biosynthesis or maturation of proteins of the Sox system and suggesting that SoxV is part of a regulatory or catalytic system of the Sox system. Analysis of DNA sequences available from different organisms harbouring a Sox system revealed that soxVW genes are exclusively present in sox operons harbouring the soxCD genes, encoding sulfur dehydrogenase, suggesting that SoxCD might be a redox partner of SoxV. No complementation of the ccdA mutant P. pantotrophus TP43 defective in cytochrome c maturation was achieved by expression of soxV in trans, demonstrating that the high identity of SoxV and CcdA does not correspond to functional homology., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.28523-0