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A single amino acid determines the catalytic efficiency of two alkenal double bond reductases produced by the liverwort Plagiochasma appendiculatum
Author(s) -
Wu Yifeng,
Cai Yuanheng,
Sun Yi,
Xu Ruixue,
Yu Haina,
Han Xiaojuan,
Lou Hongxiang,
Cheng Aixia
Publication year - 2013
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2013.07.051
Subject(s) - chemistry , double bond , catalysis , stereochemistry , amino acid , biochemistry , organic chemistry
Alkenal double bond reductases (DBRs) catalyze the NADPH‐dependent reduction of the α,β‐unsaturated double bond of many secondary metabolites. Two alkenal double bond reductase genes PaDBR1 and PaDBR2 were isolated from the liverwort species Plagiochasma appendiculatum . Recombinant PaDBR2 protein had a higher catalytic activity than PaDBR1 with respect to the reduction of the double bond present in hydroxycinnamyl aldehydes. The residue at position 56 appeared to be responsible for this difference in enzyme activity. The functionality of a C56 to Y56 mutation in PaDBR1 was similar to that of PaDBR2. Further site‐directed mutagenesis and structural modeling suggested that the phenol ring stacking between this residue and the substrate was an important determinant of catalytic efficiency.