Methyl halide transferase (, ''MCT'', methyl chloride transferase, ''S-adenosyl-L-methionine:halide/bisulfide methyltransferase'', ''AtHOL1'', ''AtHOL2'', ''AtHOL3'', ''HMT'', ''S-adenosyl-L-methionine: halide ion methyltransferase'', ''SAM:halide ion methyltransferase'') is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

with

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

''S-adenosylmethionine:iodide methyltransferase''. This enzyme catalyses the following

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

S-adenosyl-L-methionine ''S''-Adenosyl methionine (SAM), also known under the commercial names of SAMe, SAM-e, or AdoMet, is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur throug ...

iodide An iodide ion is the ion I−. Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine defic ...

\rightleftharpoons

S-adenosyl-L-homocysteine +

methyl iodide Iodomethane, also called methyl iodide, and commonly abbreviated "MeI", is the chemical compound with the formula CH3I. It is a dense, colorless, volatile liquid. In terms of chemical structure, it is related to methane by replacement of one h ...

This enzyme contributes to the

methyl In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many ...

halide In chemistry, a halide (rarely halogenide) is a binary chemical compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative (or more electropositive) than the halogen, to make a fluor ...

emissions from ''

Arabidopsis thaliana ''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small flowering plant native to Eurasia and Africa. ''A. thaliana'' is considered a weed; it is found along the shoulders of roads and in disturbed land. A winter a ...

''.

Chloride transfer

The

salt marsh A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated ...

plant ''Batis maritima'' contains the enzyme

methyl chloride transferase Methyl halide transferase (, ''MCT'', methyl chloride transferase, ''S-adenosyl-L-methionine:halide/bisulfide methyltransferase'', ''AtHOL1'', ''AtHOL2'', ''AtHOL3'', ''HMT'', ''S-adenosyl-L-methionine: halide ion methyltransferase'', ''SAM:halide ...

that catalyzes the synthesis of

chloromethane Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula . One of the haloalkanes, it is a colorless, odorless, flammable gas. Methyl chloride is a crucial reagent in industrial ...

(CH₃Cl) from S-adenosine-L-methionine and chloride. This protein has been purified and expressed in ''

E. coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

'', and seems to be present in other organisms such as white rot fungi (''

Phellinus pomaceus ''Phellinus pomaceus'' is a plant pathogen particularly common on ''Prunus ''Prunus'' is a genus of trees and shrubs, which includes (among many others) the fruits plums, cherries, peaches, nectarines, apricots, and almonds. Native to t ...

''), red algae ('' Endocladia muricata''), and the ice plant (''

Mesembryanthemum crystallinum ''Mesembryanthemum crystallinum'' is a prostrate succulent plant native to Africa, Sinai and southern Europe, and naturalized in the New World. The plant is covered with large, glistening bladder cells or water vesicles, reflected in its common n ...

''), each of which is a known CH₃Cl producer.

References

External links

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