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Alteration of a single amino acid changes the substrate specificity of dihydroflavonol 4‐reductase
Author(s) -
Johnson Eric T.,
Ryu Sunhyo,
Yi Hankuil,
Shin Byongchul,
Cheong Hyeonsook,
Choi Giltsu
Publication year - 2001
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2001.00962.x
Subject(s) - petunia , orange (colour) , substrate (aquarium) , enzyme , biosynthesis , substrate specificity , biochemistry , biology , reductase , amino acid , anthocyanin , chemistry , botany , gene , horticulture , ecology
Summary Many plant species exhibit a reduced range of flower colors due to the lack of an essential gene or to the substrate specificity of a biosynthetic enzyme. Petunia does not produce orange flowers because dihydroflavonol 4‐reductase (DFR) from this species, an enzyme involved in anthocyanin biosynthesis, inefficiently reduces dihydrokaempferol, the precursor to orange pelargonidin‐type anthocyanins. The substrate specificity of DFR, however, has not been investigated at the molecular level. By analyzing chimeric DFR s of Petunia and Gerbera , we identified a region that determines the substrate specificity of DFR. Furthermore, by changing a single amino acid in this presumed substrate‐binding region, we developed a DFR enzyme that preferentially reduces dihydrokaempferol. Our results imply that the substrate specificity of DFR can be altered by minor changes in DFR.