Methyl halide transferase explained

Methyl halide transferase
Ec Number:	2.1.1.165

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 with systematic name S-adenosylmethionine:iodide methyltransferase.^{[1] [2] [3] [4] [5] [6]} This enzyme catalyses the following chemical reaction

\rightleftharpoons S-adenosyl-L-homocysteine + methyl iodide

This enzyme contributes to the methyl halide emissions from Arabidopsis thaliana.

Chloride transfer

The salt marsh plant Batis maritima contains the enzyme methyl chloride transferase that catalyzes the synthesis of chloromethane (CH₃Cl) from S-adenosine-L-methionine and chloride.^[7] This protein has been purified and expressed in E. coli, and seems to be present in other organisms such as white rot fungi (Phellinus pomaceus),^[2] red algae (Endocladia muricata), and the ice plant (Mesembryanthemum crystallinum), each of which is a known CH₃Cl producer.^[8]

Notes and References

1. Expression of Batis maritima methyl chloride transferase in Escherichia coli . Ni, X. . Hager, L.P. . Proc. Natl. Acad. Sci. USA . 1999 . 96 . 3611–3615 . 10097085 . 10.1073/pnas.96.7.3611 . 7 . 22342. 1999PNAS...96.3611N . free .
2. Biochemical characterization of chloromethane emission from the wood-rotting fungus Phellinus pomaceus . Saxena, D. . Aouad, S. . Attieh, J. . Saini, H.S. . Appl. Environ. Microbiol. . 1998 . 64 . 2831–2835 . 9687437 . 8 . 10.1128/AEM.64.8.2831-2835.1998 . 106779. 1998ApEnM..64.2831S .
3. Purification and characterization of a novel methyltransferase responsible for biosynthesis of halomethanes and methanethiol in Brassica oleracea . Attieh, J.M. . Hanson, A.D. . Saini, H.S. . J. Biol. Chem. . 1995 . 270 . 9250–9257 . 7721844 . 10.1074/jbc.270.16.9250 . 16. free .
4. Involvement of S-adenosylmethionine-dependent halide/thiol methyltransferase (HTMT) in methyl halide emissions from agricultural plants: isolation and characterization of an HTMT-coding gene from Raphanus sativus (daikon radish) . Itoh, N. . Toda, H. . Matsuda, M. . Negishi, T. . Taniguchi, T. . Ohsawa, N. . BMC Plant Biol. . 2009 . 9 . 116 . 19723322 . 10.1186/1471-2229-9-116 . 2752461 . free .
5. Purification and characterization of a monohalomethane-producing enzyme S-adenosyl-L-methionine: halide ion methyltransferase from a marine microalga, Pavlova pinguis . Ohsawa, N. . Tsujita, M. . Morikawa, S. . Itoh, N. . Biosci. Biotechnol. Biochem. . 2001 . 65 . 2397–2404 . 11791711 . 10.1271/bbb.65.2397 . 11. free .
6. Characterization of three halide methyltransferases in Arabidopsis thaliana . Nagatoshi, Y. . Nakamura, T. . Plant Biotechnol. . 2007 . 24 . 5 . 503–506 . 10.5511/plantbiotechnology.24.503. free .
7. Ni X, Hager LP . 1998 . cDNA Cloning of Batis maritima Methyl Chloride Transferase . Purification of the Enzyme . Proc Natl Acad Sci USA . 95 . 12866–71 . 10.1073/pnas.95.22.12866 . 9789006 . 22 . 23635. free .
8. Ni X, Hager LP . 1999 . Expression of Batis maritima Methyl Chloride Transferase in Escherichia coli . Proc Natl Acad Sci USA . 96 . 3611–5 . 10.1073/pnas.96.7.3611 . 10097085 . 7 . 22342. 1999PNAS...96.3611N . free .