title: Functional characterization of a StyS sensor kinase reveals distinct domains associated with intracellular and extracellular sensing of styrene in P. putida CA-3.
abstract: Bacterial two-component systems (TCSs) are of vital importance in the translation of rapidly changing environmental conditions into appropriate cellular regulatory responses enabling adaptation, growth, and survival. The diverse range of environmental signals that TCSs can process, coupled with discrete modular domains within TCS proteins, offers considerable potential for the rational design of bio-sensor and/or bio-reporter strains. In this study we functionally characterize the multi-domain StyS sensor kinase associated with sensing of the aromatic pollutant styrene by Pseudomonas putida CA-3. Deletion analysis of discrete domains was performed and the ability of the truncated StyS sensor proteins to activate a cognate reporter system in an E. coli host assessed. The essential histidine kinase and PAS input domains were identified for StyS dependent activation of the reporter system. However, co-expression of an ABC-transporter protein StyE, previously linked to styrene transport in P. putida CA-3, enabled activation of the reporter system with a StyS construct containing a non-essential PAS input domain, suggesting a novel role for intracellular detection and/or activation. Site directed mutagenesis and amino acid deletions were employed to further characterize the PAS sensing domains of both input regions. The potential implications of these findings in the use of multi-domain sensor kinases in rational design strategies and the potential link between transport and intracellular sensing are discussed.
authors.affiliation: School of Microbiology and Environmental Research Institute; University College Cork; Cork, Ireland.
authors.forename: Niall D
authors.initials: ND
authors.lastname: O'Leary
authors.affiliation: School of Microbiology and Environmental Research Institute; University College Cork; Cork, Ireland.
authors.forename: Aisling
authors.initials: A
authors.lastname: Mooney
authors.affiliation: School of Microbiology and Environmental Research Institute; University College Cork; Cork, Ireland.
authors.forename: Mark
authors.initials: M
authors.lastname: O'Mahony
authors.affiliation: School of Microbiology and Environmental Research Institute; University College Cork; Cork, Ireland.
authors.forename: Alan Dw
authors.initials: AD
authors.lastname: Dobson
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D004789:Enzyme Activation / Q000187:drug effects; D045604:Extracellular Fluid / Q000187:drug effects / Q000378:metabolism; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011494:Protein Kinases / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016958:Pseudomonas putida / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013329:Structure-Activity Relationship; D020058:Styrene / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D018528:ATP-Binding Cassette Transporters; D020058:Styrene; D011494:Protein Kinases
keywords: ABC-transporter; PAS domains; Pseudomonas putida; histidine kinase; styrene; two-component