TsdC, a unique lipoprotein from Wolinella succinogenes that enhances tetrathionate reductase activity of TsdA

Abstract

The diheme cytochromes c of the widespread TsdA family are bifunctional thiosulfate dehydrogenase/tetrathionate reductases. Here, biochemical information was collected about TsdA from the Epsilonproteobacterium Wolinella succinogenes (WsTsdA). The situation in W. succinogenes is unique since TsdA is closely associated with the unprecedented lipoprotein TsdC encoded immediately downstream of tsdA in the same direction of transcription. WsTsdA purified from Escherichia coli catalyzed both thiosulfate oxidation and tetrathionate reduction. After co-production of TsdC and WsTsdA in E. coli, TsdC was found to mediate membrane attachment of TsdA and to ensure its full catalytic activity. This effect was much stronger in the tetrathionate-reducing than in the thiosulfate-oxidizing direction. It is concluded that the TsdAC complex predominantly acts as a tetrathionate reductase in vivo.

Regulation of Respiratory Pathways in Campylobacterota: A Review

“…A. butzleri contains an oxygen-stable pyruvate kinase instead of the oxygen-labile POR enzyme and also contains the canonical nuoEF genes instead of the Campylobacterota specific nuoXY genes (Miller et al, 2007). Based on genome analysis and for some compounds experimental proof, they can use H 2 , formate, sulfite, sulfide, thiosulfate, x-amines, lactate, malate, and NADH as electron donors and oxygen, nitrate, nitrite, TMAO/DMSO tetrathionate, and fumarate as electron acceptors (Miller et al, 2007; Martinez-Malaxetxebarria et al, 2012; Liu et al, 2013; Han and Perner, 2015; Kurth et al, 2017). Of the host-associated Campylobacterota, A. butzleri possesses the highest number (102) of regulatory genes (Table 1).…”

“…Probably due to the more restricted environment it occupies, a reduced number of 70 transcription regulator genes are found in the genome of W. succinogenes (Table 1; Baar et al, 2003). This restricted environment however contains a large variety of electron donor and acceptors as W. succinogenes can use formate, hydrogen, sulfide, pyruvate 2-oxoglutarate, succinate, and even humics as electron donor and NO, O 2 , nitrate, nitrite tetrathionate, DMSO, sulfite, fumarate, arsenate, polysulfide, and selenate as electron acceptor (Lorenzen et al, 1993, 1994; Biel et al, 1996; Lovley et al, 1999; Kroger et al, 2002; Kern et al, 2011; Kurth et al, 2017). Transcription of the W. succinogenes complexes that reduce fumarate (Frd), nitrate (Nap), polysulfide (Psr), and DMSO (Dms) are all induced when cultures are grown with their corresponding substrate as electron acceptor (Figure 1; Lorenzen et al, 1993, 1994; Kern and Simon, 2016).…”

Heme ligation and redox chemistry in two bacterial thiosulfate dehydrogenase (TsdA) enzymes

“…For Av TsdA the maximum rate of oxidative catalysis greatly exceeds that of reductive catalysis. For TsdA enzymes isolated to date from other organisms (4–7) the relative rates of these two activities also correlate with their metabolic role, however, the molecular basis of these differing behaviors remains unclear.…”

A biochemical view on the biological sulfur cycle

“…The food-borne intestinal pathogen Campylobacter jejuni may follow a similar strategy (Kurth et al, 2016a;Liu et al, 2013). Tetrathionate reduction has also been detected in Wolinella succinogenes, a close relative of C. jejuni (Kurth et al, 2017). Tetrathionate respiration has also been reported for environmentally abundant organisms such as Shewanella species.…”