Bacterial motility and behaviour
Co-workers: Nicolas Delalez, Andreas Dieppold, Nelly Dubarry, Christopher Jones, Rakesh Pandey, Kathryn Scott, James Allen, Sheng-Wen Chiu, Matthew Smith, Andrea Szollossi, Stuart Thomas, Elaine Byles.
We investigate the dynamics of bacterial sensory transduction and the control of bacterial motility. Rhodobacter sphaeroides controls the stopping frequency of its single flagellum by integrating signals from two chemosensory pathways, one responding to the extracellular environments and localised at the cell poles and one responding to the metabolic state and localised at mid cell. We are interested in the communication between the sensory and adaptation mechanisms of the two pathways as a model for sensory network integration in general.
We use techniques from ranging computerised image analysis, biochemistry, molecular genetics through to bioinformatics and computer modelling to investigate aspects of the regulation and dynamics of the sensory pathways. The output of the chemosensory pathway is regulation of the switching frequency of the bacterial rotary motor. The mechanisms involved in transducing an ion gradient into mechanical work are unclear. Using single molecule optical techniques, molecular tweezers and a regulated ion gradient we are investigating the differences between stopping and switching motors, the dynamics of the proteins within the motors and the role of the ion gradient in both rotation and motor integrity.
Briegel, A, Ladinsky MS, Oikonomou C, Jones CW,. Harris MJ, Fowler DJ, Chang Y-W, Thompson LK, Armitage JP and Jensen GJ (2014) Structure of bacterial cytoplasmic chemoreceptor arrays and implications for chemotactic signaling eLife 3:e02151. DOI: 10.7554/eLife.02151
Rosser, G, Baker, RE, Armitage, JP, Fletcher, AG (2014) Modelling and analysis of bacterial tracks suggest an active reorientation mechanism in Rhodobacter sphaeroides J Roy Soc Interface (in press)
Tipping,MJ, Steel, BC, Delalez, NJ, Berry RM and Armitage, JP (2013) In vivo control of the E. coli proton motive force and its effect on flagellar motor dynamics Mol Microbiol 87:338-47
Kojadinovic, M, Armitage, JP, Tindall, MJ and Wadhams, GH (2013) Rhodobacter sphaeroides chemotaxis response kinetics: Complexities in signalling, similarities in responses. J Roy Soc Interface. 10 : 20121001
Obara, B., Roberts, MAJ, Armitage, JP and Grau, V. (2013) Identification and characterisation of bacteria in Differential Interference Contrast microscopy images. BMC Bioinformatics 14:134 doi:10.1186/1471-2105-14-134
Chang, Y-C, Armitage, JP, Papachristodoulou, A, Wadhams, GH (2013) A single phosphatase can convert a robust step response into a tuneable or adaptive response. Microbiol. 159:1276-85
Chiu, S-W, Roberts, MAJ, Leake, MC and Armitage, JP (2013) Positioning of FtsZ and chemosensory proteins through the Rhodobacter sphaeroides cell cycle MolMicrobiol 90: 322-327
Rosser, G, Fletcher, AG, Wilkinson, DA, de Beyer, JA, Yates, CA, Armitage, JP, Maini, PK and Baker, RE (2013) Novel methods for analysing bacterial tracks reveal persistence in Rhodobacter sphaeroides PLoS Comp Biol 9(10):e1003276
Tipping, MJ, Delalez, NJ, Lim, R, Berry, RM and Armitage, JP (2013) Load dependent assembly of the bacterial flagellar motor. MBio 4(4). doi:pii: e00551-13
Scott KA, Jefferys, EE, Hall, BA, Roberts MAJ, and. Armitage, JP (2012) Bacterial chemotaxis in Regulatory Networks in Bacteria ed A. Filloux, pub. Horizon Scientific Press. Ch9, pp 223-259
Hamadeh AO, August E, Roberts MAJ, Maini PK, Armitage JP, Ingalls BP, Papachristodoulou A (2011) Feedback control architecture of the R. sphaeroides chemotaxis network. IEEE Conference on Decision and Control and European Control Conference: 3014-3019
Tindall, M.J., Gaffney, E.A., Maini, P.K., Armitage, J.P. (2012) Theoretical insights into bacterial chemotaxis. WIREs Syst Biol Med. 4: 247-59
Brown, MT, Steel, BC, Silvestrin, C, Wilkinson, DA, Delalez, NJ, Lumb, CN, Obara, B, Armitage, JP and Berry RM (2012) AviTag engineering reveals that a compliant hook capable of acting as a universal joint is essential for bundle formation and swimming in Escherichia coli J.Bacteriol 194: 3495-3501
Clausznitzer, D, Armitage, JP and Endres, RG (2012) Bacterial chemotaxis: rising complexity in Systems Microbiology: Current Topics and Applications. Eds Robertson, BD, Wren BW, Caister Academic Press pp 47-68
Scott, KA, and Armitage, JP (2012) Bacterial swimming behaviour in The Prokaryotes 4th EditionEditor-in-chief: Rosenberg, Eugene, DeLong, E.F.; Stackebrandt, E.; Lory, S.; Thompson, F. (Eds.) pub Springer on line
Roberts, MAJ, Hadfield, K, Tickner, S, Wadhams, GH and Armitage, JP (2012) A ParA-like protein uses non-specific chromosomal DNA binding to partition protein complexes PNAS 109: 6698-703
Youle, M, Rohwer, F, Stacy, A, Whiteley, M, Steele, BC, Delalez, NJ, Nord, AL, Berry, RM, Armitage, JP, Kamoun, S, Hogenhout, S, Diggle, SP, Gurney, J, Pollitt, EJG, Boetius, A, Cary, SC (2012) The Microbial Olympics. Nat Revs Microbiol 10: 583-588
Ryan, RP , McCarthy, Y , Kiely, PA, O'Connor, R, Farah , CF, Armitage , JP and Dow, MJ (2012) Dynamic complex formation between HD-GYP, GGDEF and PilZ domain proteins regulates motility in Xanthomonas campestris Mol Microbiol 86 :557-67
Hall, BA, Armitage, JP and Sansom, MSP (2012) Dynamics of Tsr dimers and trimers of dimers modelled in realistic liposomes reveal insights into mechanism of signalling in bacterial chemotaxis. PLoS Comp Biol 8(9): e1002685. doi:10.1371/journal.pcbi.1002685
Pilizota, T., Brown, M., Leake ,M. J., Branch, R., Berry, R.M. and Armitage, J.P. (2009) A molecular brake, not a clutch, stops the Rhodobacter sphaeroides flagellar motor. PNAS 106(28):11582-7