title: Control of MarRAB Operon in Escherichia coli via Autoactivation and Autorepression.
abstract: Choice of network topology for gene regulation has been a question of interest for a long time. How do simple and more complex topologies arise? In this work, we analyze the topology of the marRAB operon in Escherichia coli, which is associated with control of expression of genes associated with conferring resistance to low-level antibiotics to the bacterium. Among the 2102 promoters in E. coli, the marRAB promoter is the only one that encodes for an autoactivator and an autorepressor. What advantages does this topology confer to the bacterium? In this work, we demonstrate that, compared to control by a single regulator, the marRAB regulatory arrangement has the least control cost associated with modulating gene expression in response to environmental stimuli. In addition, the presence of dual regulators allows the regulon to exhibit a diverse range of dynamics, a feature that is not observed in genes controlled by a single regulator.
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India.
authors.forename: Mahendra Kumar
authors.initials: MK
authors.lastname: Prajapat
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India.
authors.forename: Kirti
authors.initials: K
authors.lastname: Jain
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India. Electronic address: saini@che.iitb.ac.in.
authors.forename: Supreet
authors.initials: S
authors.lastname: Saini
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003198:Computer Simulation; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D007700:Kinetics; D008957:Models, Genetic; D009876:Operon; D018085:Regulon; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D013269:Stochastic Processes
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C080002:MarA protein, E coli; C080004:MarR protein, E coli; D012097:Repressor Proteins; C080003:multiple antibiotic resistance protein B