title: The D-Lactate Dehydrogenase from Sporolactobacillus inulinus Also Possessing Reversible Deamination Activity.
abstract: Hydroxyacid dehydrogenases are responsible for the conversion of 2-keto acids to 2-hydroxyacids and have a wide range of biotechnological applications. In this study, a D-lactate dehydrogenase (D-LDH) from a Sporolactobacillus inulinus strain was experimentally verified to have both the D-LDH and glutamate dehydrogenase (GDH) activities (reversible deamination). The catalytic mechanism was demonstrated by identification of key residues from the crystal structure analysis and site-directed mutagenesis. The Arg234 and Gly79 residues of this enzyme play a significant role in both D-LDH and GDH activities. His295 and Phe298 in DLDH744 were identified to be key residues for lactate dehydrogenase (LDH) activity only whereas Tyr101 is a unique residue that is critical for GDH activity. Characterization of the biochemical properties contributes to understanding of the catalytic mechanism of this novel D-lactate dehydrogenase enzyme.
authors.affiliation: CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China.
authors.forename: Lingfeng
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou, 311121, PR China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Xu
authors.affiliation: CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, PR China.
authors.forename: Limin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Tianjin Radiation and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300192, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Dong
authors.affiliation: CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
mesh_terms: D056449:Bacillales / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D020134:Catalytic Domain; D003641:Deamination; D007700:Kinetics; D045022:Lactate Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D010802:Phylogeny
chemical_list: D045022:Lactate Dehydrogenases; C071195:D-lactate dehydrogenase