The phage shock protein (psp) operon (pspABCDE) may play a significant role in the competition for survival under nutrient- or energy-limited conditions. PspE catalyzes the sulfur-transfer reaction from thiosulfate to cyanide, to form sulfite and thiocyanate. hydrogen cyanide + thiosulfate = 2 H+ + sulfite + thiocyanate.

MFKKGLLALALVFSLPVFAAEHWIDVRVPEQYQQEHVQGAINIPLKEVKERIATAVPDKN DTVKVYCNAGRQSGQAKEILSEMGYTHVENAGGLKDIAMPKVKG105

	PMID	Title & Author	Abstract	Year
0	11997041	PspE (phage-shock protein E) of Escherichia coli is a rhodanese.Hendrik Adams , Wieke Teertstra, Margot Koster, Jan Tommassen	The psp (phage-shock protein) operon of Escherichia coli is induced when the bacteria are infected by filamentous phage and under several other stress conditions. The physiological role of the individual Psp proteins is still not known. We demonstrate here that the last gene of the operon, pspE, encodes a thiosulfate:cyanide sulfurtransferase (EC 2.8.1.1; rhodanese). Kinetic analysis revealed that catalysis occurs via a double displacement mechanism as described for other rhodaneses. The K(m)s for SSO3(2-) and CN- were 4.6 and 27 mM, respectively.	2002
1	19088907	Biochemical and Genetic Characterization of PspE and GlpE, Two Single-domain Sulfurtransferases of Escherichia coli.Hui Cheng , Janet L Donahue, Scott E Battle, W Keith Ray, Timothy J Larson	The pspE and glpE genes of Escherichia coli encode periplasmic and cytoplasmic single-domain rhodaneses, respectively, that catalyzes sulfur transfer from thiosulfate to thiophilic acceptors. Strains deficient in either or both genes were constructed. Comparison of rhodanese activity in these strains revealed that PspE provides 85% of total rhodanese activity, with GlpE contributing most of the remainder. PspE activity was four times higher during growth on glycerol versus glucose, and was not induced by conditions that induce expression of the psp regulon. The glpE/pspE mutants displayed no apparent growth phenotypes, indicating that neither gene is required for biosynthesis of essential sulfur-containing molecules. PspE was purified by using cation exchange chromatography. Two distinct active peaks were eluted and differed in the degree of stable covalent modification, as assessed by mass spectrometry. The peak eluting earliest contained the equivalent mass of two additional sulfur atoms, whereas the second peak contained mainly one additional sulfur. Kinetic properties of purified PspE were consistent with catalysis occurring via a double-displacement mechanism via an enzyme-sulfur intermediate involving the active site cysteine. K(m)s for SSO(3) (2-) and CN(-) were 2.7 mM and 32 mM, respectively, and k(cat) was 64(s-1). The enzyme also catalyzed transfer of sulfur from thiosulfate to dithiothreitol, ultimately releasing sulfide.	2008
2	23940650	The putative thiosulfate sulfurtransferases PspE and GlpE contribute to virulence of Salmonella Typhimurium in the mouse model of systemic disease.Inke Wallrodt , Lotte Jelsbak, Lotte Thorndahl, Line E Thomsen, Sebastien Lemire, John E Olsen	The phage-shock protein PspE and GlpE of the glycerol 3-phosphate regulon of Salmonella enterica serovar Typhimurium are predicted to belong to the class of thiosulfate sulfurtransferases, enzymes that traffic sulfur between molecules. In the present study we demonstrated that the two genes contribute to S. Typhimurium virulence, as a glpE and pspE double deletion strain showed significantly decreased virulence in a mouse model of systemic infection. However, challenge of cultured epithelial cells and macrophages did not reveal any virulence-associated phenotypes. We hypothesized that their contribution to virulence could be in sulfur metabolism or by contributing to resistance to nitric oxide, oxidative stress, or cyanide detoxification. In vitro studies demonstrated that glpE but not pspE was important for resistance to H2O2. Since the double mutant, which was the one affected in virulence, was not affected in this assay, we concluded that resistance to oxidative stress and the virulence phenotype was most likely not linked. The two genes did not contribute to nitric oxid stress, to synthesis of essential sulfur containing amino acids, nor to detoxification of cyanide. Currently, the precise mechanism by which they contribute to virulence remains elusive.	2013

Adams H , Teertstra W , Koster M , et al. PspE (phage-shock protein E) os Escherichia coli is a rhodanese[J]. FEBS Letters, 2002, 518(1-3):173-176.