Reaction: (1) UDP-α-D-glucose + 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one = UDP + (2R)-4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside
(2) UDP-α-D-glucose + 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one = UDP + (2R)-4-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside
For diagram of reaction click here.
Glossary: 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one = DIBOA
2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one = DIMBOA
(2R)-4-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside = DIBOA β-D-glucoside
(2R)-4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside = DIMBOA β-D-glucoside
Other name(s): uridine diphosphoglucose-2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2-glucosyltransferase; BX8; BX9; benzoxazinoid glucosyltransferase; DIMBOA glucosyltransferase
Systematic name: UDP-α-D-glucose:2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2-β-D-glucosyltransferase
Comments: The enzyme is involved in the detoxification of the benzoxazinoids DIBOA (2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one) and DIMBOA (2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one) which are stored as the respective non-toxic glucosides in the vacuoles in some plants, most commonly from the family of Poaceae (grasses). Benzoxazinoids are known to exhibit antimicrobial, antifeedant, and antiinsecticidal effects and are involved in the interaction of plants with other plants, insects, or microorganisms.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 122544-56-3
References:
1. Bailey, B.A. and Larson, R.L. Hydroxamic acid glucosyltransferases from maize seedlings. Plant Physiol. 90 (1989) 1071-1076. [PMID: 16666853]
2. von Rad, U., Huttl, R., Lottspeich, F., Gierl, A. and Frey, M. Two glucosyltransferases are involved in detoxification of benzoxazinoids in maize. Plant J. 28 (2001) 633-642. [PMID: 11851909]