Catalyzes the hydrolysis of tetrathionate to generate elemental sulfur, thiosulfate and sulfate. H2O + tetrathionate = H+ + sulfate + sulfur + thiosulfate

MPSIVRNHGPHNKILLSALLLALFGWVPLASAAVAVPMDSTGPYRTVSHPENAPSGVDAG VGPSEWTHAYANPAHNAAFPVPDDAPEWIRNGVSWLFPEARAWPLANPPFGSKTYGAAEA SVTQTQFYGNALGPSVVDGVVYAESDDMFAYAVNAKTGKLIWRASPVGNNLMGNPLVIGN TVYLSAGSVAFNFANVLRYAHNPSASARGLNVSFNGIYALNRSNGKLLWYFATPGETMAT PAYDNNTLFIADGAGNAFGINATTGKQVWKTHVGGMDNMSSVTAYRHNIYFAMAIKPYLY CLNESNGHIVWKGTIPGASNTGIGDVSPAAADGVVVLDATTKPQANKKAMFSNVIRAFDA KTGAVLWTRNMGSGGKIPAFKGGVPMIHNNIVYVGNPVASTYQAYELKTGKLLWTWHVPT KVAAGAGRSAPTYYKGLLYITTGQYIFVVNPATGKELHQHHIGGQFGIESPVIVGGTVYL TNSWDWIMAIPLKTISHGS507

	PMID	Title & Author	Abstract	Year
0	17904676.0	Identification of a gene encoding a tetrathionate hydrolase in Acidithiobacillus ferrooxidans. Kanao T, Kamimura K, Sugio T.	Tetrathionate is one of the most important intermediates in dissimilatory sulfur oxidation and can itself be utilized as a sole energy source by some sulfur-oxidizing microorganisms. Tetrathionate hydrolase (4THase) plays a significant role in tetrathionate oxidation and should catalyze the initial step in the oxidative dissimilation when sulfur-oxidizing bacteria are grown on tetrathionate. 4THase activity was detected in tetrathionate-grown Acidithiobacillus ferrooxidans ATCC 23270 cells but not in iron-grown cells. A 4THase having a dimeric structure of identical 50kDa polypeptides was purified from tetrathionate-grown cells. The 4THase showed the maximum activity at pH 3.0 and high stability under acidic conditions. An open reading frame (ORF) encoding the N-terminal amino acid sequence of the purified 4THase was identified by a BLAST search using the database for the A. ferrooxidans ATCC 23270 genome. Heterologous expression of the gene in Escherichia coli resulted in the formation of inclusion bodies of the protein in an inactive form. Antisera against the recombinant protein clearly recognized the purified native 4THase, indicating that the ORF encoded the 4THase.	2007.0
1	24727223.0	Construction and characterization of tetH overexpression and knockout strains of Acidithiobacillus ferrooxidans. Yu Y, Liu X, Wang H, Li X, Lin J.	Acidithiobacillus ferrooxidans is a major participant in consortia of microorganisms used for bioleaching. It can obtain energy from the oxidation of Fe(2+), H2, S(0), and various reduced inorganic sulfur compounds (RISCs). Tetrathionate is a key intermediate during RISC oxidation, hydrolyzed by tetrathionate hydrolase (TetH), and used as sole energy source. In this study, a tetH knockout (ΔtetH) mutant and a tetH overexpression strain were constructed and characterized. The tetH overexpression strain grew better on sulfur and tetrathionate and possessed a higher rate of tetrathionate utilization and TetH activity than the wild type. However, its cell yields on tetrathionate were much lower than those on sulfur. The ΔtetH mutant could not grow on tetrathionate but could proliferate on sulfur with a lower cell yield than the wild type's, which indicated that tetrathionate hydrolysis is mediated only by TetH, encoded by tetH. The ΔtetH mutant could survive in ferrous medium with an Fe(2+) oxidation rate similar to that of the wild type. For the tetH overexpression strain, the rate was relatively higher than that of the wild type. The reverse transcription-quantitative PCR (qRT-PCR) results showed that tetH and doxD2 acted synergistically, and doxD2 was considered important in thiosulfate metabolism. Of the two sqr genes, AFE_0267 seemed to play as important a role in sulfide oxidation as AFE_1792. This study not only provides a substantial basis for studying the function of the tetH gene but also may serve as a model to clarify other candidate genes involved in sulfur oxidation in this organism.	2014.0
2	17873067.0	Regulation of a novel Acidithiobacillus caldus gene cluster involved in metabolism of reduced inorganic sulfur compounds. Rzhepishevska OI, Valdés J, Marcinkeviciene L, Gallardo CA, Meskys R, Bonnefoy V, Holmes DS, Dopson M.	Acidithiobacillus caldus has been proposed to play a role in the oxidation of reduced inorganic sulfur compounds (RISCs) produced in industrial biomining of sulfidic minerals. Here, we describe the regulation of a new cluster containing the gene encoding tetrathionate hydrolase (tetH), a key enzyme in the RISC metabolism of this bacterium. The cluster contains five cotranscribed genes, ISac1, rsrR, rsrS, tetH, and doxD, coding for a transposase, a two-component response regulator (RsrR and RsrS), tetrathionate hydrolase, and DoxD, respectively. As shown by quantitative PCR, rsrR, tetH, and doxD are upregulated to different degrees in the presence of tetrathionate. Western blot analysis also indicates upregulation of TetH in the presence of tetrathionate, thiosulfate, and pyrite. The tetH cluster is predicted to have two promoters, both of which are functional in Escherichia coli and one of which was mapped by primer extension. A pyrrolo-quinoline quinone binding domain in TetH was predicted by bioinformatic analysis, and the presence of an o-quinone moiety was experimentally verified, suggesting a mechanism for tetrathionate oxidation.	2007.0
3	24993543.0	Whole-genome sequencing reveals novel insights into sulfur oxidation in the extremophile Acidithiobacillus thiooxidans. Yin H, Zhang X, Li X, He Z, Liang Y, Guo X, Hu Q, Xiao Y, Cong J, Ma L, Niu J, Liu X.	Background: Acidithiobacillus thiooxidans (A. thiooxidans), a chemolithoautotrophic extremophile, is widely used in the industrial recovery of copper (bioleaching or biomining). The organism grows and survives by autotrophically utilizing energy derived from the oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs). However, the lack of genetic manipulation systems has restricted our exploration of its physiology. With the development of high-throughput sequencing technology, the whole genome sequence analysis of A. thiooxidans has allowed preliminary models to be built for genes/enzymes involved in key energy pathways like sulfur oxidation.	2014.0
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5			Results: The genome of A. thiooxidans A01 was sequenced and annotated. It contains key sulfur oxidation enzymes involved in the oxidation of elemental sulfur and RISCs, such as sulfur dioxygenase (SDO), sulfide quinone reductase (SQR), thiosulfate:quinone oxidoreductase (TQO), tetrathionate hydrolase (TetH), sulfur oxidizing protein (Sox) system and their associated electron transport components. Also, the sulfur oxygenase reductase (SOR) gene was detected in the draft genome sequence of A. thiooxidans A01, and multiple sequence alignment was performed to explore the function of groups of related protein sequences. In addition, another putative pathway was found in the cytoplasm of A. thiooxidans, which catalyzes sulfite to sulfate as the final product by phosphoadenosine phosphosulfate (PAPS) reductase and adenylylsulfate (APS) kinase. This differs from its closest relative Acidithiobacillus caldus, which is performed by sulfate adenylyltransferase (SAT). Furthermore, real-time quantitative PCR analysis showed that most of sulfur oxidation genes were more strongly expressed in the S0 medium than that in the Na2S2O3 medium at the mid-log phase.
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7			Conclusion: Sulfur oxidation model of A. thiooxidans A01 has been constructed based on previous studies from other sulfur oxidizing strains and its genome sequence analyses, providing insights into our understanding of its physiology and further analysis of potential functions of key sulfur oxidation genes.

Kanao, T., Kamimura, K., and Sugio, T. (2007) Identification of a gene encoding a tetrathionate hydrolase in Acidithiobacillus ferrooxidans. J Biotechnol 132: 16–22.