Rhodanese

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Rhodanese-like domain
Rhodanase.png
Identifiers
SymbolRhodanese
PfamPF00581
InterProIPR001763
PROSITEPDOC00322
SCOPe2ora / SUPFAM
OPM superfamily413
OPM protein2mpn
CDDcd00158
Membranome571

Rhodanese, also known as rhodanase, thiosulfate sulfurtransferase, thiosulfate cyanide transsulfurase, and thiosulfate thiotransferase,[1] is a mitochondrial enzyme that detoxifies cyanide (CN) by converting it to thiocyanate (SCN).[2]

This reaction takes place in two steps. The diagram on the right shows the crystallographically-determined structure of rhodanese. In the first step, thiosulfate is reduced by the thiol group on cysteine-247 1, to form a persulfide and a sulfite 2. In the second step, the persulfide reacts with cyanide to produce thiocyanate, re-generating the cysteine thiol 1.[3]

Rhodanase2.png

This reaction is important for the treatment of exposure to cyanide, since the thiocyanate formed is around 1 / 200 as toxic.[4]:p. 15938 The use of thiosulfate solution as an antidote for cyanide poisoning is based on the activation of this enzymatic cycle.

Rhodanese shares evolutionary relationship with a large family of proteins, including

  • Cdc25 phosphatase catalytic domain.
  • non-catalytic domains of eukaryotic dual-specificity MAPK-phosphatases
  • non-catalytic domains of yeast PTP-type MAPK-phosphatases
  • non-catalytic domains of yeast Ubp4, Ubp5, Ubp7
  • non-catalytic domains of mammalian Ubp-Y
  • Drosophila heat shock protein HSP-67BB
  • several bacterial cold-shock and phage shock proteins
  • plant senescence associated proteins
  • catalytic and non-catalytic domains of rhodanese[5]

Rhodanese has an internal duplication. This domain is found as a single copy in other proteins, including phosphatases and ubiquitin C-terminal hydrolases.[6]

Human proteins containing this domain[edit]

CDC25A; CDC25B; CDC25C; DUSP; DUSP1; DUSP10; DUSP16; DUSP2; DUSP4; DUSP5; DUSP6; DUSP7; KAT; MKP7; MOCS3; MPST; TBCK; TSGA14; TST; USP8;

Nomenclature[edit]

Although the standard nomenclature rules for enzymes indicate that their names are to end with the letters "-ase", rhodanese was first described in 1933,[7] prior to the 1955 establishment of the Enzyme Commission; as such, the older name had already attained widespread usage.

Thiosulfate sulfurtransferase[edit]

thiosulfate sulfurtransferase
Identifiers
EC number2.8.1.1
CAS number9026-04-4
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO

In enzymology, a thiosulfate sulfurtransferase (EC 2.8.1.1) is an enzyme that catalyzes the chemical reaction

thiosulfate + cyanide sulfite + thiocyanate

Thus, the two substrates of this enzyme are thiosulfate and cyanide, whereas its two products are sulfite and thiocyanate.

Nomenclature[edit]

This enzyme belongs to the family of transferases, specifically the sulfurtransferases, which transfer sulfur-containing groups. The systematic name of this enzyme class is thiosulfate:cyanide sulfurtransferase. Other names in common use include thiosulfate cyanide transsulfurase, thiosulfate thiotransferase, rhodanese, and rhodanase.

References[edit]

  1. ^ EC 2.8.1.1, at the International Union of Biochemistry and Molecular Biology
  2. ^ Cipollone R, Ascenzi P, Tomao P, Imperi F, Visca P (2008). "Enzymatic detoxification of cyanide: clues from Pseudomonas aeruginosa Rhodanese". Journal of Molecular Microbiology and Biotechnology. 15 (2–3): 199–211. doi:10.1159/000121331. PMID 18685272.
  3. ^ Cipollone R, Ascenzi P, Tomao P, Imperi F, Visca P (2008). "Enzymatic detoxification of cyanide: clues from Pseudomonas aeruginosa Rhodanese". Journal of Molecular Microbiology and Biotechnology. 15 (2–3): 199–211. doi:10.1159/000121331. PMID 18685272.
  4. ^ Jaszczak E, Polkowska Ż, Narkowicz S, Namieśnik J (July 2017). "Cyanides in the environment-analysis-problems and challenges". Environmental Science and Pollution Research International. 24 (19): 15929–15948. doi:10.1007/s11356-017-9081-7. PMC 5506515. PMID 28512706.
  5. ^ "Thiosulphate sulfurtransferase, conserved site (IPR001307)". EMBL-EBI. InterPro.
  6. ^ Gliubich F, Gazerro M, Zanotti G, Delbono S, Bombieri G, Berni R (August 1996). "Active site structural features for chemically modified forms of rhodanese". The Journal of Biological Chemistry. 271 (35): 21054–61. doi:10.1074/jbc.271.35.21054. PMID 8702871.
  7. ^ Cipollone R, Ascenzi P, Visca P (February 2007). "Common themes and variations in the rhodanese superfamily". IUBMB Life. 59 (2): 51–9. doi:10.1080/15216540701206859. PMID 17454295.

External links[edit]