title: A single amino acid determines the catalytic efficiency of two alkenal double bond reductases produced by the liverwort Plagiochasma appendiculatum.
abstract: 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.
authors: Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China.
authors: Yifeng
authors: Y
authors: Wu
authors: Yuanheng
authors: Y
authors: Cai
authors: Yi
authors: Y
authors: Sun
authors: Ruixue
authors: R
authors: Xu
authors: Haina
authors: H
authors: Yu
authors: Xiaojuan
authors: X
authors: Han
authors: Hongxiang
authors: H
authors: Lou
authors: Aixia
authors: A
authors: Cheng
mesh_terms: D000447:Aldehydes / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D055162:Biocatalysis; D003545:Cysteine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D035926:Hepatophyta / Q000737:chemistry* / Q000201:enzymology; D007700:Kinetics; D062105:Molecular Docking Simulation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009249:NADP / Q000737:chemistry / Q000378:metabolism; D010088:Oxidoreductases / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014443:Tyrosine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D010940:Plant Proteins; D011994:Recombinant Proteins; D014443:Tyrosine; D009249:NADP; D010088:Oxidoreductases; D003545:Cysteine
keywords: Alkenal double bond reductase; Hydroxycinnamyl aldehyde; Molecular modeling; Plagiochasma appendiculatum; Site-directed mutagenesis