|
KMID : 0545120160260061077
|
|
Journal of Microbiology and Biotechnology
2016 Volume.26 No. 6 p.1077 ~ p.1086
|
|
|
Characterization of Glycerol Dehydrogenase from Thermoanaerobacterium thermosaccharolyticum DSM 571 and GGG Motif Identification
|
|
Wang Liang Liang
Wang Jia Jun
Shi Hao
Gu Hua Xiang
Zhang Yu
Li Xun
Wang Fei
|
|
|
Abstract
|
|
|
|
Glycerol dehydrogenases (GlyDHs) are essential for glycerol metabolism in vivo, catalyzing its reversible reduction to 1,3-dihydroxypropranone (DHA). The gldA gene encoding a putative GlyDH was cloned from Thermoanaerobacterium thermosaccharolyticum DSM 571 (TtGlyDH) and expressed in Escherichia coli. The presence of Mn2+ enhanced its enzymatic activity by 79.5%. Three highly conserved residues (Asp171, His254, and His271) in TtGlyDH were associated with metal ion binding. Based on an investigation of glycerol oxidation and DHA reduction, TtGlyDH showed maximum activity towards glycerol at 60°C and pH 8.0 and towards DHA at 60°C and pH 6.0. DHA reduction was the dominant reaction, with a lower Km(DHA) of 1.08 ± 0.13 mM and Vmax of 0.0053 ± 0.0001 mM/s, compared with glycerol oxidation, with a Km(glycerol) of 30.29 ± 3.42 mM and Vmax of 0.042 ± 0.002 mM/s. TtGlyDH had an apparent activation energy of 312.94 kJ/mol. The recombinant TtGlyDH was thermostable, maintaining 65% of its activity after a 2-h incubation at 60°C. Molecular modeling and site-directed mutagenesis analyses demonstrated that TtGlyDH had an atypical dinucleotide binding motif (GGG motif) and a basic residue Arg43, both related to dinucleotide binding.
|
|
|
KEYWORD
|
|
|
dinucleotide binding, glycerol dehydrogenase, molecular modeling, site-directed mutagenesis, Thermoanaerobacterium thermosaccharolyticum
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|