Literature summary for 2.1.1.241 extracted from

  • Handrick, V.; Robert, C.; Ahern, K.; Zhou, S.; Machado, R.; Maag, D.; Glauser, G.; Fernandez-Penny, F.; Chandran, J.; Rodgers-Melnik, E.; Schneider, B.; Buckler, E.; Boland, W.; Gershenzon, J.; Jander, G.; Erb, M.; Koellner, T.
    Biosynthesis of 8-O-methylated benzoxazinoid defense compounds in maize (2016), Plant Cell, 28, 1682-1700 .
    View publication on PubMedView publication on EuropePMC

Cloned(Commentary)

Cloned (Comment) Organism
gene BX7, DNA and amino acid sequence determination and analysis, the QTL Bb3 on chromosome 4 comprises the O-methyltransferase gene Bx7, identifies by quantitative trait locus (QTL) mapping, overview, phylogenetic tree, functional recombinant expression of N-terminally His-tagged enzyme in Escherichia coli Zea mays

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
S-adenosyl-L-methionine + 2-(2,4,7-trihydroxy-8-methoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose Zea mays i.e. TRIMBOA-Glc S-adenosyl-L-homocysteine + 2-(2,4-dihydroxy-7,8-dimethoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose
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?

Organism

Organism UniProt Comment Textmining
Zea mays B1P123
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Purification (Commentary)

Purification (Comment) Organism
recombinant N-terminally His-tagged enzyme from Escherichia coli by nickel affinity chromatography and gel filtration Zea mays

Source Tissue

Source Tissue Comment Organism Textmining
leaf
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Zea mays
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Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
S-adenosyl-L-methionine + 2-(2,4,7-trihydroxy-8-methoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose i.e. TRIMBOA-Glc Zea mays S-adenosyl-L-homocysteine + 2-(2,4-dihydroxy-7,8-dimethoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose
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?
S-adenosyl-L-methionine + 2-(2,4,7-trihydroxy-8-methoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose i.e. TRIMBOA-Glc, enzyme BX7 methylates the C-7 hydroxyl group of TRIBOA-Glc. Recombinant BX7 also accepts TRIMBOA-Glc as substrate and methylates the hydroxyl group at C-7 Zea mays S-adenosyl-L-homocysteine + 2-(2,4-dihydroxy-7,8-dimethoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose
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?

Synonyms

Synonyms Comment Organism
BX7
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Zea mays
O-methyltransferase BX7
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Zea mays
OMT BX7
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Zea mays
TRIBOA-glucoside O-methyltransferase UniProt Zea mays

Cofactor

Cofactor Comment Organism Structure
S-adenosyl-L-methionine
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Zea mays

Expression

Organism Comment Expression
Zea mays gene Bx7 is constitutively expressed and shows no significant increase in transcript accumulation after simulated herbivory additional information

General Information

General Information Comment Organism
metabolism the enzyme is involved in benzoxazinoid formation in maize, overview. A 2-oxoglutarate-dependent dioxygenase (BX13, UniProt ID A0A1P8SET2) catalyzes the conversion of 2-(2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose (DIMBOA-Glc) into a benzoxazinoid intermediate, 2-(2,4,7-trihydroxy-8-methoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose (TRIMBOA-Glc), by an uncommon reaction involving hydroxylation and a likely ortho-rearrangement of a methoxy group. TRIMBOA-Glc is then converted to 2-(2,4-dihydroxy-7,8-dimethoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose (DIM2BOA-Glc) by an O-methyltransferase BX7. Furthermore, an O-methyltransferase BX14 (UniProt ID A0A1P8SEU3) converts DIM2BOA-Glc to 2-(2-hydroxy-4,7,8-trimethoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose (HDM2BOA-Glc). HDM2BOA-Glc is known to be induced by biotic stresses such as pathogen infestation and insect feeding. The inducibility of HDM2BOA-Glc is associated with a stronger induction of genes Bx13 and Bx14. DIM2BOA-Glc and HDM2BOA-Glc specifically increase plant resistance against aphids Zea mays
evolution gene Bx7 is part of a small gene family consisting of 15 members with higher sequence similarity to each other (62 to 99%), BX7 shows high similarity to BX14 Zea mays