Abstract
BackgroundGamma-proteobacteria, such as Escherichia coli, can use a variety of respiratory substrates employing numerous aerobic and anaerobic respiratory systems controlled by multiple transcription regulators. Thus, in E. coli, global control of respiration is mediated by four transcription factors, Fnr, ArcA, NarL and NarP. However, in other Gamma-proteobacteria the composition of global respiration regulators may be different.ResultsIn this study we applied a comparative genomic approach to the analysis of three global regulatory systems, Fnr, ArcA and NarP. These systems were studied in available genomes containing these three regulators, but lacking NarL. So, we considered several representatives of Pasteurellaceae, Vibrionaceae and Yersinia spp. As a result, we identified new regulon members, functioning in respiration, central metabolism (glycolysis, gluconeogenesis, pentose phosphate pathway, citrate cicle, metabolism of pyruvate and lactate), metabolism of carbohydrates and fatty acids, transcriptional regulation and transport, in particular: the ATP synthase operon atpIBEFHAGCD, Na+-exporting NADH dehydrogenase operon nqrABCDEF, the D-amino acids dehydrogenase operon dadAX. Using an extension of the comparative technique, we demonstrated taxon-specific changes in regulatory interactions and predicted taxon-specific regulatory cascades.ConclusionA comparative genomic technique was applied to the analysis of global regulation of respiration in ten gamma-proteobacterial genomes. Three structurally different but functionally related regulatory systems were described. A correlation between the regulon size and the position of a transcription factor in regulatory cascades was observed: regulators with larger regulons tend to occupy top positions in the cascades. On the other hand, there is no obvious link to differences in the species' lifestyles and metabolic capabilities.
Highlights
Gamma-proteobacteria, such as Escherichia coli, can use a variety of respiratory substrates employing numerous aerobic and anaerobic respiratory systems controlled by multiple transcription regulators
In facultative anaerobe E. coli, regulation of respiration depends on the availability of electron acceptors, which are used in a specific order
The level of regulation is provided by two homologous transcription factors, NarL and NarP
Summary
Gamma-proteobacteria, such as Escherichia coli, can use a variety of respiratory substrates employing numerous aerobic and anaerobic respiratory systems controlled by multiple transcription regulators. Escherichia coli, the best-studied representative of gammaproteobacteria, can adapt to a wide variety of environmental conditions. One source of this capability is the presence of numerous aerobic and anaerobic respiratory systems. Nitrate, the most favorable electron acceptor in such conditions, represses other types of anaerobic respiration and fermentation. This control is effected by a variety of regulatory systems [1,2]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
