The GntR-Like Regulator TauR Activates Expression of Taurine Utilization Genes in Rhodobacter capsulatus

Abstract

Rhodobacter capsulatus can efficiently grow with taurine as the sole sulfur source. The products of the tpa-tauR-xsc gene region are essential for this activity. TauR, a MocR-like member of the GntR superfamily of transcriptional regulators, activates tpa transcription, as shown by analysis of wild-type and tauR mutant strains carrying a tpa-lacZ reporter fusion. Activation of the tpa promoter requires taurine but is not inhibited by sulfate, which is the preferred sulfur source. TauR directly binds to the tpa promoter, as demonstrated by DNA mobility shift assays. As expected for a transcriptional activator, the TauR binding site is located upstream of the transcription start site, which has been determined by primer extension. Site-directed promoter mutations reveal that TauR binds to direct repeats, an unusual property that has to date been shown for only one other member of the MocR subfamily, namely, GabR from Bacillus subtilis. In contrast, all other members of the GntR family analyzed so far bind to inverted repeats.

Positive transcriptional control of the pyridoxal phosphate biosynthesis genes pdxST by the MocR-type regulator PdxR of Corynebacterium glutamicum ATCC 13032

“…A similar genetic organization of candidate DNA-binding sites was detected in the nucleotide sequence linked to DNA binding of TauR, a MocR-type regulator that activates the expression of taurine utilization genes in Rhodobacter capsulatus (Wiethaus et al, 2008). The respective DNA region contains a 10 bp direct repeat with the sequence CTGGAC(T/C)TAA and a 13 bp spacing (Wiethaus et al, 2008). Interestingly, the candidate DNAbinding sites of TauR and the 12 bp motif 2 recognized by PdxR share the similar sequence TGGAYYTA, whereas the stretch of DNA sequence similarity to the 11 bp motif 1 is shorter (TGGWCY).…”

“…Hence, these candidate DNA-binding sites are located on the same face of the DNA double helix. A similar genetic organization of candidate DNA-binding sites was detected in the nucleotide sequence linked to DNA binding of TauR, a MocR-type regulator that activates the expression of taurine utilization genes in Rhodobacter capsulatus (Wiethaus et al, 2008). The respective DNA region contains a 10 bp direct repeat with the sequence CTGGAC(T/C)TAA and a 13 bp spacing (Wiethaus et al, 2008).…”

Control of Copper Resistance and Inorganic Sulfur Metabolism by Paralogous Regulators in Staphylococcus aureus

“…Another possible inducer of cst expression is the sulfonated ␤-amino acid taurine or an as yet unidentified taurine metabolite. S. aureus does not encode a taurine repressor TauR; thus, taurine might also be indirectly sensed by CstR as sulfite or another metabolite (39). Taurine is a highly abundant amino acid in mammals and a dedicated Na ϩ -dependent uptake system for taurine is encoded by ssuBAC in S. aureus (35).…”

Different bacterial strategies to degrade taurocholate

“…5a). The presumptive regulator (TauR), an orthologue of which has deWned regulatory properties (Wiethaus et al 2008), enables induction of an ABC transporter for taurine uptake (TauABC) (see Eichhorn et al 2000) and degradation proceedes via taurine dehydrogenase (TauXY), as well as sulfoacetaldehyde acetyltransferase (Xsc) and phosphotransacetylase (Pta). The sulWte exporter is unknown, while the sulWte dehydrogenase is presumably one of four candidates for periplasmic SorA indicated elsewhere (Denger et al 2008).…”