Reaction: dimethylallyl diphosphate + leachianone G = diphosphate + sophoraflavanone G
For diagram of reaction, click here
Glossary: leachianone G = (–-)-(2S)-2′-hydroxy-8-dimethylallylnaringenin = (–)-(2S)-2-(2,4-dihydroxyphenyl)-5,7-dihydroxy-8-(3-methylbut-2-en-1-yl)chroman-4-one
sophoraflavanone G = (2S)-2-(2,4-dihydroxyphenyl)-5,7-dihydroxy-8-[(2R)-2-(prop-1-en-2-yl)hex-4-en-1-yl]chroman-4-one
Other name(s): LG 2"-dimethylallyltransferase; leachianone G 2"-dimethylallyltransferase; LGDT
Systematic name: dimethylallyl-diphosphate:leachianone-G 2"-dimethylallyltransferase
Comments: This membrane-bound enzyme is located in the plastids and requires Mg2+ for activity. The reaction forms the lavandulyl sidechain of sophoraflavanone G by transferring a dimethylallyl group to the 2" position of another dimethylallyl group attached at postiion 8 of leachianone G. The enzyme is specific for dimethylallyl diphosphate as the prenyl donor, as it cannot be replaced by isopentenyl diphosphate or geranyl diphosphate. Euchrenone a7 (a 5-deoxy derivative of leachianone G) and kenusanone I (a 7-methoxy derivative of leachianone G) can also act as substrates, but more slowly. Along with EC 1.14.13.103 (8-dimethylallylnaringenin 2'-hydroxylase) and EC 2.5.1.70 (naringenin 8-dimethylallyltransferase), this enzyme forms part of the sophoraflavanone-G biosynthesis pathway.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Zhao, P., Inoue, K., Kouno, I. and Yamamoto, H. Characterization of leachianone G 2"-dimethylallyltransferase, a novel prenyl side-chain elongation enzyme for the formation of the lavandulyl group of sophoraflavanone G in Sophora flavescens Ait. cell suspension cultures. Plant Physiol. 133 (2003) 1306-1313. [PMID: 14551337]