title: Extremely high intracellular concentration of glucose-6-phosphate and NAD(H) in Deinococcus radiodurans.
abstract: Deinococcus radiodurans is highly resistant to ionizing radiation and UV radiation, and oxidative stress caused by such radiations. NADP(H) seems to be important for this resistance (Slade and Radman, Microbiol Mol Biol Rev 75:133-191; Slade, Radman, Microbiol Mol Biol Rev 75:133-191, 2011), but the mechanism underlying the generation of NADP(H) or NAD(H) in D. radiodurans has not fully been addressed. Intracellular concentrations of NAD+, NADH, NADP+, and NADPH in D. radiodurans are also not determined yet. We found that cell extracts of D. radiodurans catalyzed reduction of NAD(P)+in vitro, indicating that D. radiodurans cells contain both enzymes and a high concentration of substrates for this activity. The enzyme and the substrate were attributed to glucose-6-phosphate dehydrogenase and glucose-6-phosphate of which intracellular concentration was extremely high. Unexpectedly, the intracellular concentration of NAD(H) was also much greater than that of NADP(H), suggesting some significant roles of NADH. These unusual features of this bacterium would shed light on a new aspect of physiology of this bacterium.
authors.affiliation: Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Yamashiro
authors.affiliation: Faculty of Science and Engineering, Department of Life Science, Setsunan University, Neyagawa, Osaka, Japan.
authors.forename: Kousaku
authors.initials: K
authors.lastname: Murata
authors.affiliation: Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan. kawais@kais.kyoto-u.ac.jp.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kawai
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D034301:Deinococcus / Q000378:metabolism*; D019298:Glucose-6-Phosphate / Q000378:metabolism*; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D009243:NAD / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D009243:NAD; D019298:Glucose-6-Phosphate; D005954:Glucosephosphate Dehydrogenase
keywords: Deinococcus radiodurans; Glucose-6-phosphate; Glucose-6-phosphate dehydrogenase; NAD(H); NADP(H)