Manipulation of the anoxic metabolism in escherichia coli by ArcB deletion variants in the ArcBA two-component system
Bioprocesses conducted under conditions with restricted O2 supply are increasingly exploited for the synthesis of reduced biochemicals using different biocatalysts. The model facultative anaerobe Escherichia coli has elaborate sensing and signal transduction mechanisms for redox control in response...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | Argentina |
| Institución: | Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales |
| Repositorio: | Biblioteca Digital (UBA-FCEN) |
| Idioma: | inglés |
| OAI Identifier: | paperaa:paper_00992240_v78_n24_p8784_Bidart |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00992240_v78_n24_p8784_Bidart |
| Access Level: | acceso abierto |
| Palabra clave: | Acetyl coenzyme A Anoxic conditions Bioprocesses D-glucose D-lactate Deletion mutants Deletion variants E. coli Electron acceptor Enzymatic activities Facultative anaerobes Gene expression patterns Metabolic flux Metabolic flux distribution Metabolite profiles Mutant strain Phenotypic traits Phospho-transfer Response regulators Sensor kinase Signal transduction mechanism Transmembranes Two component systems Wild types Wild-type strain Enzymes Escherichia coli Ethanol Gene expression Glucose Metabolites Plants (botany) Signal transduction Metabolism alcohol arcA protein, E coli arcB protein, E coli Escherichia coli protein glucose lactic acid membrane protein nicotinamide adenine dinucleotide outer membrane protein protein kinase repressor protein succinic acid anoxic conditions biochemical composition catalyst coliform bacterium metabolism mutation oxygen redox conditions anaerobic growth article enzymology fermentation gene deletion genetics Anaerobiosis Bacterial Outer Membrane Proteins Escherichia coli Proteins Fermentation Lactic Acid Membrane Proteins Metabolic Networks and Pathways NAD Protein Kinases Repressor Proteins Sequence Deletion Succinic Acid Arca |
| Sumario: | Bioprocesses conducted under conditions with restricted O2 supply are increasingly exploited for the synthesis of reduced biochemicals using different biocatalysts. The model facultative anaerobe Escherichia coli has elaborate sensing and signal transduction mechanisms for redox control in response to the availability of O2 and other electron acceptors. The ArcBA two-component system consists of ArcB, a membrane-associated sensor kinase, and ArcA, the cognate response regulator. The tripartite hybrid kinase ArcB possesses a transmembrane, a PAS, a primary transmitter (H1), a receiver (D1), and a phosphotransfer (H2) domain. Metabolic fluxes were compared under anoxic conditions in a wild-type E. coli strain, its ΔarcB derivative, and two partial arcB deletion mutants in which ArcB lacked either the H1 domain or the PAS-H1-D1 domains. These analyses revealed that elimination of different segments in ArcB determines a distinctive distribution of D-glucose catabolic fluxes, different from that observed in the ΔarcB background. Metabolite profiles, enzyme activity levels, and gene expression patterns were also investigated in these strains. Relevant alterations were observed at the P-enol-pyruvate/pyruvate and acetyl coenzyme A metabolic nodes, and the formation of reduced fermentation metabolites, such as succinate, D-lactate, and ethanol, was favored in the mutant strains to different extents compared to the wild-type strain. These phenotypic traits were associated with altered levels of the enzymatic activities operating at these nodes, as well as with elevated NADH/NAD+ ratios. Thus, targeted modification of global regulators to obtain different metabolic flux distributions under anoxic conditions is emerging as an attractive tool for metabolic engineering purposes. © 2012, American Society for Microbiology. |
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