Bioinformatic analysis of sulfotransferases from an unexplored gut microbe, Sutterella wadsworthensis 3_1_45B: Possible roles towards detoxification via sulfation by the members of the human gut microbiome

Sulfation, primarily facilitated by sulfotransferases, plays a crucial role in the detoxification pathways of both endogenous substances and xenobiotics, enhancing their water solubility and promoting metabolism and elimination. Traditionally, this bioconversion has been attributed to a family of human cytosolic sulfotransferases (hSULTs) known for their high sequence similarity and dependence on 3-phosphoadenosine 5-phosphosulfate (PAPS) as a sulfate donor. However, recent studies have revealed the presence of PAPS-dependent sulfotransferases within gut commensals, indicating that the gut microbiome may harbor a diverse array of sulfotransferase enzymes and may contribute to detoxification processes via sulfation. In this study, we investigated the prevalence of sulfotransferases in the members of the human gut microbiome. Interestingly, we stumbled upon a different class of sulfotransferases, known as aryl-sulfate sulfotransferases (ASSTs). ASSTs have been characterized from a few different prokaryotes including E. coli. ASSTs do not utilize PAPS which is the default sulfate donor for the human sulfotransferases. Our bioinformatics analyses revealed that the gut microbial genus Sutterella possesses a significant number of asst genes, possibly encoding multiple ASST enzymes. Fluctuations in the microbes of the genus Sutterella have been associated with various health conditions. For this reason, we characterized 17 different ASSTs from Sutterella wadsworthensis 3_1_45B with bioinformatics. Our findings reveal that SwASSTs share similarities with E. coli ASST but also exhibit significant structural variations and sequence diversity. These differences might drive potential functional diversification and likely reflect an evolutionary divergence from their PAPS-dependent counterparts.