Dr Mark S Thomas BSc PhD

Department of Infection and Immunity
L Floor
The University of Sheffield Medical School
Beech Hill Road
Sheffield
S10 2RX
United Kingdom
Tel: +44 (0)114 226 1227
Fax: +44 (0)114 226 8898
Email: m.s.thomas@sheffield.ac.uk
Secretary - Jean Lazenby
Tel: +44 (0)114 271 2237
Email: j.lazenby@sheffield.ac.uk
Biography
I obtained my PhD in the Department of Biochemistry at the University of Southampton followed by a postdoctoral stint in the laboratory of Masayasu Nomura at the Institute for Enzyme Research, UW-Madison, and subsequently relocated with him to UC-Irvine. I then spent some time working with Richard Flavell's group at IPSR in Cambridge and with Robert Glass at the University of Nottingham. I joined the University of Sheffield in 1994.
Research Interests
Virulence genes and their regulation in the Gram-negative opportunistic pathogen, Burkholderia cenocepacia. Particular areas of interest include:
- Iron acquisition mechanisms
- Protein toxins and their mechanism of secretion
- Response to environmental stress, particularly the role of extracytoplasmic function (ECF) sigma factors.
Mechanisms of transcription regulation in Gram-negative bacteria. Particular areas of interest include:
- Transcription activation
- ECF sigma factors
- Growth rate-dependent control
Teaching Interests
Currently, I teach bacterial molecular genetics, microbial pathogenicity, and microbiology to science undergraduates, medical students and Masters students.
Current Projects
- Secretion of toxins by B. cenocepacia
- Characterisation of B. cenocepacia genes that are upregulated by environmental stress
- How does B. cenocepacia survive in a low iron environment?
Key Publications
Identification and regulation of virulence genes in Burkholderia
- Lochowska, A., Iwanicka-Nowicka, R., Zielak, A., Modelewska, A., Thomas, M.S. and Hryniewicz, M.M. (2011). Regulation of sulfur assimilation pathways in Burkholderia cenocepacia: genes controlled by the SsuR transcription factor. J. Bacteriol., 193, 1843-1853.
- Asghar, A.H., Shastri, S., Dave, E., Wowk, I., Agnoli, K., Cook, A.M. and Thomas, M.S. (2011). The pobA gene of Burkholderia cenocepacia encodes a Group I Sfp-type phosphopantetheinyl transferase required for biosynthesis of the siderophores ornibactin and pyochelin. Microbiology, 157, 349-361.
- Aschtgen, M.-S., Thomas, M.S. and Cascales, E. (2010). Anchoring the type VI secretion system to the peptidoglycan: TssL, TagL, TagP...what else? Virulence, 1 (6), 1-6.
- Shalom, G., Shaw, J.G. and Thomas, M.S. (2007). In vivo expression technology identifies a type VI secretion system in Burkholderia pseudomallei that is induced upon invasion of macrophages. Microbiology, 153, 2689-2699.
- Thomas, M.S. (2007). Iron acquisition mechanisms of the Burkholderia cepacia complex. Biometals, 20, 431-452.
- Iwanicka-Nowicka, R., Zielak, A., Cook, A.M., Thomas, M.S. and Hryniewicz, M. (2007). Regulation of sulfur assimilation pathways in Burkholderia cenocepacia: identification of transcription factors CysB and SsuR and their role in control of target genes. J. Bacteriol., 189, 1675-1688.
- Agnoli, K., Lowe, C.A., Farmer, K.L., Husnain, I. and Thomas, M.S. (2006). The ornibactin biosynthesis and transport genes of Burkholderia cenocepacia are regulated by an ECF σ factor which is a part of the Fur regulon. J. Bacteriol., 3631-3644.
- Farmer and Thomas (2004). Isolation and characterization of Burkholderia cenocepacia mutants deficient in pyochelin production: pyochelin biosynthesis is sensitive to sulphur availability. J. Bacteriol. 186, 270-277.
- Subsin, B., Thomas, M.S., Katzenmeier, G., Shaw, J.G., Tungpradapkul, S. and Kunakorn, M. (2003). Role of the stationary phase sigma factor, RpoS, of Burkholderia pseudomallei in reponse to physiological stress conditions. J. Bacteriol., 185, 7008-7014.
- Lowe, C.A., Asghar, A.H., Shalom, G., Shaw, J.G. and Thomas, M.S. (2001). The Burkholderia cepacia fur gene: co-localisation with omlA and absence of regulation by iron. Microbiology, 147, 1303-1314.
- Shalom, G., Shaw, J.G. and Thomas, M.S. (2000). pGSTp: An IVET compatible promoter probe vector conferring resistance to trimethoprim. BioTechniques, 29, 954-958.
Transcription regulation in bacteria
- Twist, K-A., Husnain, S.I., Franke, J.D., Jain, D., Campbell, E.A., Nickels, B.E., Thomas, M.S., Darst, S.A. and Westblade, L.F. (2011). A novel method for the production of in vivo-assembled, recombinant Escherichia coli RNA polymerase lacking the α C-terminal domain. Protein Science, 20, 986-995.
- Husnain, S.I., Busby, S.J.W. and Thomas, M.S. (2009). Downregulation of the Escherichia coli guaB promoter by upstream-bound CRP. J. Bacteriol., 191, 6094-6104.
- Husnain, S.I. and Thomas, M.S. (2008). Downregulation of the Escherichia coli guaB promoter by FIS. Microbiol. 154, 1729-1738.
- Husnain, S.I. and Thomas, M.S. (2008). The UP element is necessary but not sufficient for growth rate-dependent control of the Escherichia coli guaB promoter. J. Bacteriol., 190, 2450-2457.
- Kedzierska, B., Szambowska, A., Lee, D.J., Herman-Antosiewicz, A., Busby, S.J.W., Wegrzyn, G. and Thomas, M.S. (2007). The C-terminal domain of the Escherichia coli RNA polymerase α subunit plays a role in the CI-dependent activation of the bacteriophage λpM promoter. Nucleic Acids Res., 35, 2311-2320.
- Husnain, S.I., Meng, W., Busby, S.J.W. & Thomas, M.S. (2004). Escherichia coli can tolerate insertions but not deletions in the RNA polymerase α subunit linker. Biochim. Biophys. Acta, 1678, 47-56.
- Kedzierska, B., Lee, D., Busby, S.J.W., Wêgrzyn, G. and Thomas, M.S. (2004). Role of the RNA polymerase α subunits in CII-dependent activation of the bacteriophage λpE promoter: identification of important residues and positioning of the α C-terminal domains. Nucleic Acids Res. 32, 834-841.
- Savery, N.J., Lloyd, G.S., Busby, S.J.W., Thomas, M.S., Ebright, R.H. and Gourse, R.L. (2002). Determinants in the C-terminal domain of the Escherichia coli RNA polymerase α subunit important for transcription at Class I CRP-dependent promoters. J. Bacteriol., 184, 2273-2280.
- Meng, W., Belyaeva, T., Savery, N.J., Busby, S., Ross, W.E., Gaal, T., Gourse, R.L. and Thomas, M.S. (2001). UP element-dependent transcription at the Escherichia coli rrnB P1 promoter: positional requirements and role of the RNA polymerase α subunit linker. Nucleic Acids Res., 29, 4166-4178.
- Meng, W., Savery, N.J., Busby, S.J.W. and Thomas, M.S. (2000). The E. coli RNA polymerase α subunit linker: length requirements for transcription activation at CRP-dependent promoters. EMBO J., 19, 1555-1566.
