Project description:Many sulfur-oxidizing prokaryotes oxidize sulfur compounds through a combination of initial extracytoplasmic and downstream cytoplasmic reactions. Facultative sulfur oxidizers adjust transcription to sulfur availability. While sulfur-oxidizing enzymes and transcriptional repressors have been extensively studied, sulfur import into the cytoplasm and how regulators sense external sulfur are poorly understood. Addressing this gap, we show that SoxT1A and SoxT1B, which resemble YeeE/YedE-family thiosulfate transporters and are encoded alongside sulfur oxidation and transcriptional regulation genes, fulfill these roles in the Alphaproteobacterium Hyphomicrobium denitrificans. RT-qPCR provided initial evidence that SoxT1A and SoxT1B from H. denitrificans may be intricate components of the oxidation pathway and/or involved in its transcriptional regulation. Here, we extend these analyses with genome-wide mRNA-Seq data for the reference strain, comparing transcription in the absence and presence of 2 mM thiosulfate
Project description:Bacteria use different strategies to sense and respond to reduced sulfur compounds such as sulfide or thiosulfate. In the methylotrophic Alphaproteobacterium Hyphomicrobium denitrificans, which uses thiosulfate as an accessory electron donor, this involves two distinct but related ArsR-type transcriptional repressors, sHdrR and SoxR. Here, we focused on identifying target genes regulated by these repressors. This was achieved by generating individual deletions of each regulator gene, and performing comparative RNA-seq analysis.
Project description:Genome-enabled studies of anaerobic, nitrate-dependent Fe(II) oxidation in the chemolithoautotrophic bacterium Thiobacillus denitrificans