EC |
2.1.1.212 |
Accepted name: |
2,7,4′-trihydroxyisoflavanone 4′-O-methyltransferase |
Reaction: |
S-adenosyl-L-methionine + 2,4′,7-trihydroxyisoflavanone = S-adenosyl-L-homocysteine + 2,7-dihydroxy-4′-methoxyisoflavanone |
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For diagram of daidzein biosynthesis, click here |
Other name(s): |
SAM:2,7,4′-trihydroxyisoflavanone 4′-O-methyltransferase; HI4′OMT; HMM1; MtIOMT5; S-adenosyl-L-methionine:2,7,4′-trihydroxyisoflavanone 4′-O-methyltransferase |
Systematic name: |
S-adenosyl-L-methionine:2,4′,7-trihydroxyisoflavanone 4′-O-methyltransferase |
Comments: |
Specifically methylates 2,4′,7-trihydroxyisoflavanone on the 4′-position. No activity with isoflavones [2]. The enzyme is involved in formononetin biosynthesis in legumes [1]. The protein from pea (Pisum sativum) also methylates (+)-6a-hydroxymaackiain at the 3-position (cf. EC 2.1.1.270, (+)-6a-hydroxymaackiain 3-O-methyltransferase) [4]. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Akashi, T., Sawada, Y., Shimada, N., Sakurai, N., Aoki, T. and Ayabe, S. cDNA cloning and biochemical characterization of S-adenosyl-L-methionine: 2,7,4′-trihydroxyisoflavanone 4′-O-methyltransferase, a critical enzyme of the legume isoflavonoid phytoalexin pathway. Plant Cell Physiol. 44 (2003) 103–112. [PMID: 12610212] |
2. |
Deavours, B.E., Liu, C.J., Naoumkina, M.A., Tang, Y., Farag, M.A., Sumner, L.W., Noel, J.P. and Dixon, R.A. Functional analysis of members of the isoflavone and isoflavanone O-methyltransferase enzyme families from the model legume Medicago truncatula. Plant Mol. Biol. 62 (2006) 715–733. [DOI] [PMID: 17001495] |
3. |
Liu, C.J., Deavours, B.E., Richard, S.B., Ferrer, J.L., Blount, J.W., Huhman, D., Dixon, R.A. and Noel, J.P. Structural basis for dual functionality of isoflavonoid O-methyltransferases in the evolution of plant defense responses. Plant Cell 18 (2006) 3656–3669. [DOI] [PMID: 17172354] |
4. |
Akashi, T., VanEtten, H.D., Sawada, Y., Wasmann, C.C., Uchiyama, H. and Ayabe, S. Catalytic specificity of pea O-methyltransferases suggests gene duplication for (+)-pisatin biosynthesis. Phytochemistry 67 (2006) 2525–2530. [DOI] [PMID: 17067644] |
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[EC 2.1.1.212 created 2011] |
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EC |
2.1.1.270 |
Accepted name: |
(+)-6a-hydroxymaackiain 3-O-methyltransferase |
Reaction: |
S-adenosyl-L-methionine + (+)-6a-hydroxymaackiain = S-adenosyl-L-homocysteine + (+)-pisatin |
Glossary: |
(+)-6a-hydroxymaackiain = (6aR,12aR)-6H-[1,3]dioxolo[5,6][1]benzofuro[3,2-c]chromene-3,6a(12aH)-diol
(+)-pisatin = (6aR,12aR)-3-methoxy-6H-[1,3]dioxolo[5,6][1]benzofuro[3,2-c]chromen-6a(12aH)-ol |
Other name(s): |
HM3OMT; HMM2 |
Systematic name: |
S-adenosyl-L-methionine:(+)-6a-hydroxymaackiain 3-O-methyltransferase |
Comments: |
The protein from the plant Pisum sativum (garden pea) methylates (+)-6a-hydroxymaackiain at the 3-position. It also methylates 2,7,4′-trihydroxyisoflavanone on the 4′-position (cf. EC 2.1.1.212, 2,7,4-trihydroxyisoflavanone 4-O-methyltransferase) with lower activity. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Preisig, C.L., Matthews, D.E. and Vanetten, H.D. Purification and characterization of S-adenosyl-L-methionine:6a-hydroxymaackiain 3-O-methyltransferase from Pisum sativum. Plant Physiol. 91 (1989) 559–566. [PMID: 16667069] |
2. |
Wu, Q., Preisig, C.L. and VanEtten, H.D. Isolation of the cDNAs encoding (+)6a-hydroxymaackiain 3-O-methyltransferase, the terminal step for the synthesis of the phytoalexin pisatin in Pisum sativum. Plant Mol. Biol. 35 (1997) 551–560. [PMID: 9349277] |
3. |
Liu, C.J., Deavours, B.E., Richard, S.B., Ferrer, J.L., Blount, J.W., Huhman, D., Dixon, R.A. and Noel, J.P. Structural basis for dual functionality of isoflavonoid O-methyltransferases in the evolution of plant defense responses. Plant Cell 18 (2006) 3656–3669. [DOI] [PMID: 17172354] |
4. |
Akashi, T., VanEtten, H.D., Sawada, Y., Wasmann, C.C., Uchiyama, H. and Ayabe, S. Catalytic specificity of pea O-methyltransferases suggests gene duplication for (+)-pisatin biosynthesis. Phytochemistry 67 (2006) 2525–2530. [DOI] [PMID: 17067644] |
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[EC 2.1.1.270 created 2013] |
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