Reaction: (1) (2R)-4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside + H2O =
2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one + D-glucose
(2) (2R)-4-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside + H2O =
2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one + D-glucose
Glossary: DIMBOA glucoside = (2R)-4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside
DIBOA glucoside = (2R)-4-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside
Other name(s): DIMBOAGlc hydrolase; DIMBOA glucosidase
Systematic name: (2R)-4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl β-D-glucopyranoside β-D-glucosidase
Comments: The enzyme from Triticum aestivum (wheat) has a higher affinity for DIMBOA glucoside than DIBOA glucoside. With Secale cereale (rye) the preference is reversed.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Sue, M., Ishihara, A. and Iwamura, H. Purification and characterization of a hydroxamic acid glucoside β-glucosidase from wheat (Triticum aestivum L.) seedlings. Planta 210 (2000) 432-438. [PMID: 10750901]
2. Sue, M., Ishihara, A. and Iwamura, H. Purification and characterization of a β-glucosidase from rye (Secale cereale L.) seedlings. Plant Sci. 155 (2000) 67-74. [PMID: 10773341]
3. Czjzek, M., Cicek, M., Zamboni, V., Bevan, D.R., Henrissat, B. and Esen, A. The mechanism of substrate (aglycone) specificity in β-glucosidases is revealed by crystal structures of mutant maize β-glucosidase-DIMBOA, -DIMBOAGlc, and -dhurrin complexes. Proc. Natl. Acad. Sci. USA 97 (2000) 13555-13560. [PMID: 11106394]
4. Nikus, J., Esen, A. and Jonsson, L.M.V. Cloning of a plastidic rye (Secale cereale) β-glucosidase cDNA and its expression in Escherichia coli. Physiol. Plantarum 118 (2003) 337-348.
5. Sue, M., Yamazaki, K., Yajima, S., Nomura, T., Matsukawa, T., Iwamura, H. and Miyamoto, T. Molecular and structural characterization of hexameric β-D-glucosidases in wheat and rye. Plant Physiol. 141 (2006) 1237-1247. [PMID: 16751439]
6. Sue, M., Nakamura, C., Miyamoto, T. and Yajima, S. Active-site architecture of benzoxazinone-glucoside β-D-glucosidases in Triticeae. Plant Sci. 180 (2011) 268-275. [PMID: 21421370]