Rhodanese is a mitochondrial

Mitochondrion

In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometers in diameter...

 enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 that detoxifies cyanide

Cyanide

A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN−. Most cyanides are highly toxic....

 (CN^-) by converting it to thiocyanate

Thiocyanate

Thiocyanate is the anion [SCN]−. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Organic compounds containing the functional group SCN are also called thiocyanates...

 (SCN^-).

This reaction takes place in two steps. The diagram on the right shows the crystallographically

X-ray crystallography

X-ray crystallography is a method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and causes the beam of light to spread into many specific directions. From the angles and intensities of these diffracted beams, a crystallographer can produce a...

-determined structure of rhodanese. In the first step, thiosulfate

Thiosulfate

Thiosulfate is an oxyanion of sulfur. The prefix thio indicates that thiosulfate ion is a sulfate ion with one oxygen replaced by a sulfur. Thiosulfate occurs naturally and is produced by certain biochemical processes...

 reacts with the thiol

Thiol

In organic chemistry, a thiol is an organosulfur compound that contains a carbon-bonded sulfhydryl group...

 group on Cysteine

Cysteine

Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...

-247 1, to form a disulfide

Disulfide

In chemistry, a disulfide usually refers to the structural unit composed of a linked pair of sulfur atoms. Disulfide usually refer to a chemical compound that contains a disulfide bond, such as diphenyl disulfide, C6H5S-SC6H5....

 2. In the second step, the disulfide reacts with cyanide to produce thiocyanate, itself being converted back into the "normal" thiol

Thiol

In organic chemistry, a thiol is an organosulfur compound that contains a carbon-bonded sulfhydryl group...

 1.
This reaction is important for the decontamination of cyanide, since the thiocyanate formed is relatively harmless. 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 (see ).

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

Human proteins containing this domain

CDC25A

CDC25A

Cell division cycle 25 homolog A , also known as CDC25A, is a mammalian gene.-Interactions:CDC25A has been shown to interact with ASK1, Epidermal growth factor receptor, C-Raf, CHEK1, Cyclin E1, PIM1 and YWHAB.-Further reading:...

; CDC25B

CDC25B

M-phase inducer phosphatase 2 is an enzyme that in humans is encoded by the CDC25B gene.-Interactions:CDC25B has been shown to interact with MAPK14, Casein kinase 2, alpha 1, CHEK1, MELK, Estrogen receptor alpha, YWHAB, YWHAZ, YWHAH and YWHAE....

; CDC25C

CDC25C

M-phase inducer phosphatase 3 is an enzyme that in humans is encoded by the CDC25C gene.-Interactions:CDC25C has been shown to interact with MAPK14, CHEK1, PCNA, PIN1, PLK3 and NEDD4.-Further reading:...

; DUSP; DUSP1

DUSP1

Dual specificity protein phosphatase 1 is an enzyme that in humans is encoded by the DUSP1 gene.-Interactions:DUSP1 has been shown to interact with MAPK14, MAPK1 and MAPK8.-Further reading:...

; DUSP10

DUSP10

Dual specificity protein phosphatase 10 is an enzyme that in humans is encoded by the DUSP10 gene.-Interactions:DUSP10 has been shown to interact with MAPK14 and MAPK8.-Further reading:...

; DUSP16

DUSP16

Dual specificity protein phosphatase 16 is an enzyme that in humans is encoded by the DUSP16 gene.-Interactions:DUSP16 has been shown to interact with MAPK14 and MAPK8IP1.-Further reading:...

;
DUSP2

DUSP2

Dual specificity protein phosphatase 2 is an enzyme that in humans is encoded by the DUSP2 gene.-Further reading:...

; DUSP4

DUSP4

Dual specificity protein phosphatase 4 is an enzyme that in humans is encoded by the DUSP4 gene.-Further reading:...

; DUSP5

DUSP5

Dual specificity protein phosphatase 5 is an enzyme that in humans is encoded by the DUSP5 gene.-Further reading:...

; DUSP6

DUSP6

Dual specificity phosphatase 6, also known as DUSP6, is an enzyme that in humans is encoded by the DUSP6 gene.- Function :The protein encoded by this gene is a member of the dual specificity protein phosphatase subfamily. These phosphatases inactivate their target kinases by dephosphorylating both...

; DUSP7

DUSP7

Dual specificity protein phosphatase 7 is an enzyme that in humans is encoded by the DUSP7 gene.- Function :Dual-specificity phosphatases constitute a large heterogeneous subgroup of the type I cysteine-based protein-tyrosine phosphatase superfamily. DUSPs are characterized by their ability to...

; KAT

Kat

Kat is a common nickname for the feminine given name Katherine, Kathleen, Katarina, Katrina, Kathryn, and variations. It is also a homonym or whimsical spelling for "cat."Kat or KAT may refer to:-Science:...

; MKP7; MOCS3

MOCS3

Adenylyltransferase and sulfurtransferase MOCS3 is an enzyme that in humans is encoded by the MOCS3 gene.-Further reading:...

;
MPST

MPST

3-mercaptopyruvate sulfurtransferase is an enzyme that in humans is encoded by the MPST gene.-Further reading:...

; TBCK; TSGA14; TST

TST

The acronym TST can refer to:*Ternary search tree, a computer science term for a data structure used in search problems*Toeplitz Symmetric Tridiagonal, a specific type of matrix*Toronto School of Theology, Canada...

; USP8

USP8

Ubiquitin carboxyl-terminal hydrolase 8 is an enzyme that in humans is encoded by the USP8 gene.-Interactions:USP8 has been shown to interact with RNF41 and STAM2.-Further reading:...

;