title: Carbon Catabolite Repression and the Related Genes of ccpA, ptsH and hprK in Thermoanaerobacterium aotearoense.
abstract: The strictly anaerobic, Gram-positive bacterium, Thermoanaerobacterium aotearoense SCUT27, is capable of producing ethanol, hydrogen and lactic acid by directly fermenting glucan, xylan and various lignocellulosically derived sugars. By using non-metabolizable and metabolizable sugars as substrates, we found that cellobiose, galactose, arabinose and starch utilization was strongly inhibited by the existence of 2-deoxyglucose (2-DG). However, the xylose and mannose consumptions were not markedly affected by 2-DG at the concentration of one-tenth of the metabolizable sugar. Accordingly, T. aotearoense SCUT27 could consume xylose and mannose in the presence of glucose. The carbon catabolite repression (CCR) related genes, ccpA, ptsH and hprK were confirmed to exist in T. aotearoense SCUT27 through gene cloning and protein characterization. The highly purified Histidine-containing Protein (HPr) could be specifically phosphorylated at Serine 46 by HPr kinase/phosphatase (HPrK/P) with no need to add fructose-1,6-bisphosphate (FBP) or glucose-6-phosphate (Glc-6-P) in the reaction mixture. The specific protein-interaction of catabolite control protein A (CcpA) and phosphorylated HPr was proved via affinity chromatography in the absence of formaldehyde. The equilibrium binding constant (KD) of CcpA and HPrSerP was determined as 2.22 ± 0.36 nM by surface plasmon resonance (SPR) analysis, indicating the high affinity between these two proteins.
authors.affiliation: Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.
authors.forename: Muzi
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.
authors.forename: Jufang
authors.initials: J
authors.lastname: Wang
authors.affiliation: Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Kidney, the Institute of Life Sciences, Chinese PLA General Hospital, Beijing, China.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D002244:Carbon / Q000378:metabolism*; D057465:Catabolite Repression / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D019298:Glucose-6-Phosphate / Q000235:genetics; D006639:Histidine / Q000235:genetics; D008660:Metabolism / Q000235:genetics*; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D046950:Thermoanaerobacterium / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D006639:Histidine; D019298:Glucose-6-Phosphate; D002244:Carbon; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C110847:HPr kinase; D017346:Protein Serine-Threonine Kinases