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EC 2.8.4.3 Details

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EC number

2.8.4.3

Accepted name

tRNA-2-methylthio-N⁶-dimethylallyladenosine synthase

Reaction

N⁶-(3-methylbut-2-en-1-yl)-adenine³⁷ in tRNA + sulfur-(sulfur carrier) + 2 S-adenosyl-L-methionine + reduced electron acceptor = N⁶-(3-methylbut-2-en-1-yl)-2-(methylsulfanyl)adenine³⁷ in tRNA + S-adenosyl-L-homocysteine + (sulfur carrier) + L-methionine + 5′-deoxyadenine + electron acceptor (overall reaction);;(1a) N⁶-(3-methylbut-2-en-1-yl)-adenine³⁷ in tRNA + sulfur-(sulfur carrier) + S-adenosyl-L-methionine + reduced electron acceptor = N⁶-(3-methylbut-2-en-1-yl)-2-thioadenine³⁷ in tRNA + (sulfur carrier) + L-methionine + 5′-deoxyadenine + electron acceptor ;;(1b) S-adenosyl-L-methionine + N⁶-(3-methylbut-2-en-1-yl)-2-thioadenine³⁷ in tRNA = S-adenosyl-L-homocysteine + N⁶-(3-methylbut-2-en-1-yl)-2-(methylsulfanyl)adenine³⁷ in tRNA

Other name(s)

MiaB, 2-methylthio-N-6-isopentenyl adenosine synthase, tRNA-i6A37 methylthiotransferase, tRNA (N⁶-dimethylallyladenosine³⁷):sulfur-(sulfur carrier),S-adenosyl-L-methionine C²-methylthiotransferase

Systematic name

tRNA N⁶-(3-methylbut-2-en-1-yl)-adenine³⁷:sulfur-(sulfur carrier),S-adenosyl-L-methionine C²-(methylsulfanyl)transferase

Comment

This bacterial enzyme binds two [4Fe-4S] clusters as well as the transferred sulfur [3]. The enzyme is a member of the superfamily of S-adenosyl-L-methionine-dependent radical (radical AdoMet) enzymes. The sulfur donor is believed to be one of the [4Fe-4S] clusters, which is sacrificed in the process, so that in vitro the reaction is a single turnover. The identity of the electron donor is not known.

History

created 2014, modified 2015

EC Tree

1 Oxidoreductases

1.1 Acting on the CH-OH group of donors

1.2 Acting on the aldehyde or oxo group of donors

1.3 Acting on the CH-CH group of donors

1.4 Acting on the CH-NH₂ group of donors

1.5 Acting on the CH-NH group of donors

1.6 Acting on NADH or NADPH

1.7 Acting on other nitrogenous compounds as donors

1.8 Acting on a sulfur group of donors

1.9 Acting on a heme group of donors

1.10 Acting on diphenols and related substances as donors

1.11 Acting on a peroxide as acceptor

1.11.1 Peroxidases

1.11.2 Peroxygenases

1.12 Acting on hydrogen as donor

1.13 Acting on single donors with incorporation of molecular oxygen (oxygenases)

1.14 Acting on paired donors, with incorporation or reduction of molecular oxygen

1.15 Acting on superoxide as acceptor

1.16 Oxidizing metal ions

1.16.1 With NAD⁺ or NADP⁺ as acceptor

1.16.3 With oxygen as acceptor

1.16.5 With a quinone or similar compound as acceptor

1.16.8 With a flavin as acceptor

1.16.9 With a copper protein as acceptor

1.16.98 With other, known, physiological acceptors

1.16.99 With unknown physiological acceptors

1.17 Acting on CH or CH₂ groups

1.18 Acting on iron-sulfur proteins as donors

1.19 Acting on reduced flavodoxin as donor

1.20 Acting on phosphorus or arsenic in donors

1.21 Catalysing the reaction X-H + Y-H = X-Y

1.22 Acting on halogen in donors

1.22.1 With NAD⁺ or NADP⁺ as acceptor

1.23 Reducing C-O-C group as acceptor

1.97 Other oxidoreductases

1.98 Enzymes using H₂ as reductant (deleted subclass)

1.99 Other enzymes using O₂ as oxidant (deleted subclass)

2 Transferases

2.1 Transferring one-carbon groups

2.2 Transferring aldehyde or ketonic groups

2.3 Acyltransferases

2.4 Glycosyltransferases

2.5 Transferring alkyl or aryl groups, other than methyl groups

2.6 Transferring nitrogenous groups

2.7 Transferring phosphorus-containing groups

2.8 Transferring sulfur-containing groups

2.8.1 Sulfurtransferases

2.8.2 Sulfotransferases

2.8.3 CoA-transferases

2.8.4 Transferring alkylthio groups

2.8.4.1 coenzyme-B sulfoethylthiotransferase

2.8.4.2 arsenate-mycothiol transferase

2.8.4.3 tRNA-2-methylthio-N⁶-dimethylallyladenosine synthase

2.8.4.4 [ribosomal protein S12] (aspartate⁸⁹-C³)-methylthiotransferase

2.8.4.5 tRNA (N⁶-L-threonylcarbamoyladenosine³⁷-C²)-methylthiotransferase

2.8.4.6 S-methyl-1-thioxylulose 5-phosphate methylthiotransferase

2.8.5 Thiosulfotransferases

2.9 Transferring selenium-containing groups

2.10 Transferring molybdenum- or tungsten-containing groups