In our laboratory we study molecular aspects of transcription. Our main focus is on sigma factors – transcriptional regulatory proteins that are the master regulators of gene expression in bacteria.
We are particularly interested in understanding the mechanism by which non-canonical sigma factors interact with RNA polymerase, target holoenzyme to promoter DNA, and stabilize open-complex promoter intermediates during the transcription initiation process.
Note to all applicants: Due to volume of applications, I cannot guarantee a response to each inquiry. We will contact you if we intend to further consider your application. For applicants outside of Canada, arranging for funding (scholarships) from your resident country will dramatically improve chances of favourable consideration.
Gaballa, A., MacLellan, S.R., and J.D. Helmann. 2011. Transcription activation by the siderophore sensor Btr is mediated by ligand-dependent stimulation of promoter clearance. Nucl.Acids.Res. NAR-02400-M-2011. In press.
MacLellan, S.R., Guariglia-Oropeza, V., Gaballa, A. and J.D. Helmann. 2009. A two-subunit sigma factor activates transcription in Bacillus subtilis. PNAS. 106: 21323-21328.
MacLellan, S.R., Eiamphungporn, W., and J.D. Helmann. 2008. ROMA: an in vitro approach to defining target genes for transcription regulators. Methods. 47: 73-77.
MacLellan, S.R., Helmann, J.D., and H. Antelmann. 2008. Distribution and role of a newly identified sigma factor in the bacilli: YvrI is a component of the acid-stress response in Bacillus subtilis. J. Bacteriol. 191: 931-939.
MacLellan, S.R., Wecke, T., and J.D. Helmann. 2008. A previously unidentified sigma factor and two accessory proteins regulate oxalate decarboxylase expression in Bacillus subtilis. Mol. Microbiol. 69: 954-967.
MacLellan, S.R., MacLean, A.M., and T.M Finan. 2006. Promoter prediction in the rhizobia. Microbiology. 152: 1751-1763.