B.A. Wellesley College 1980
Ph.D. State University of New York, Buffalo 1987
Professor and Chair, Premedical Biology Program, Department of Biological Sciences, Florida Institute of Technology, 2007-present.
Associate Professor and Chair, Premedical Biology Program, Department of Biological Sciences, Florida Institute of Technology, 2000-2007
Assistant Professor and Chair, Premedical Biology Program, Department of Biological Sciences, Florida Institute of Technology, 1994-2000
Research Scientist, Department of Biological Sciences, Florida Institute of Technology, 1989-1994
NIH Post-Doctoral Fellow, Biology Department, University of Rochester, Rochester, NY 1987-1989
Some of the questions being studied in our labs are: What proteins bind to the origin of DNA replication? At what time in the cell division cycle to these proteins bind? How is the timing of DNA replication coupled to the growth rate of the cell? How are complexes assembled and disassembled so that replication timing is precisely controlled? In order to answer these questions, we use a combination of biochemical, physiological and genetic techniques. Many of our studies use the extremely well characterized gut bacterium, Escherichia coli. Recently, however, the lab has begun to examine initiation of DNA replication and growth control of other pathogenic bacteria, such as Mycobacteria tuberculosis and Vibrio cholerae. Study of cell cycle control in diverse organisms may reveal fundamental regulatory mechanisms, which will help us understand cell growth in all organisms.
Rozgaja, T, Grimwade, J.E, , Iqbal, M., Czerwonka, C., Vora. M., and Leonard, A.C. (2011) Two oppositely-oriented arrays of low affinity recognition sites in oriC guide progressive binding of DnaA during E. coli pre-RC assembly, Mol. Microbiol., 82:475-488
Saxena, R., Rozgaja, T., Grimwade, J.E., and Crooke, E. (2011) Remodeling of nucleoprotein complexes is independent of a mutant AAA+ protein's nucleotide state, J. Biol. Chem., 286:33770-33777
Leonard, A.C., and Grimwade, J.E. (2011) Regulation of DnaA assembly and activity: taking directions from the genome, Annual Review of Microbiology, 65:19-35
Leonard, A.C., and Grimwade, J.E. (2010) Regulating DnaA complex assembly: it's time to fill the gaps, Curr. Opin. Microbiol., 13:766-772
Leonard, A. C., and Grimwade, J. E. (2010) Chapter 4.4.1, Initiation of DNA Replication. In A. Bck, R. Curtiss III, J. B. Kaper, P. D. Karp, F. C. Neidhardt, T. Nystrm, J. M. Slauch, C. L. Squires, and D. Ussery (ed.), EcoSalEscherichia coli and Salmonella: cellular and molecular biology. http://www.ecosal.org. ASM Press, Washington, DC.
Miller, D.T., Grimwade, J. E., Betteridge, T., Rozgaja, T., Torgue, J.JC., and Leonard, A.C. (2009) Bacterial origin recognition complexes direct assembly of higher order DnaA oligomeric structures, Proc. Natl. Acad. Sci. USA, 106:18479-18484
Grimwade, J.E., and Leonard, A.C. (2009) Initiating chromosome replication in E. coli: it makes sense to recycle. Genes & Dev., 23:1145-1150
Leonard, A. C., and Grimwade, J.E. (2009) Chromosome Replication and Segregation, in Encyclopedia of Microbiology, Third Edition. M. Schaechter, ed. pp. 493-506 Oxford: Elsevier
Grimwade, J.E., Torgue, J.C.C., McGarry, K.C., Rozgaja, T., Enloe, S.T., and Leonard, A.C. (2007) Mutational analysis reveals E. coli oriC interacts with both DnaA-ATP and DnaA-ADP during pre-RC assembly, Mol. Microbiol., 66: 428-439
Nievera, C., Torgue, J.J.C., Grimwade, J.E., and Leonard, A.C. (2006) SeqA blocking of DnaA-oriC interaction ensures staged assembly of the E. coli pre-RC, Mol. Cell, 24: 581-592.
Madiraju, M.V.V.S., Moomey, M., Neuenschwander, P.F., Muniruzzaman, S., Yamamoto, K., Grimwade, J.E. and Rajagopalan, M. (2006) The intrinsic ATPase activity of Mycobacterium tuberculosis DnaA promotes rapid oligomerization of DnaA on oriC. Mol. Microbiol. 59:18761890
Leonard, A.C., and J.E. Grimwade. (2005) Building a bacterial orisome: emergence of new regulatory features for replication origin unwinding. Mol. Microbiol. 55: 978-485.
McGarry, K.C., V.T. Ryan, J.E. Grimwade and A.C. Leonard (2004) Two discriminatory binding sites in the Escherichia coli replication origin are required for DNA strand opening by initiator DnaAATP. Proc. Natl., Acad. Sci., USA 101: 2811-2816.
Ryan, V.T., J.E. Grimwade, J.E. Camara, E. Crooke and A.C. Leonard (2004) Precise E. coli pre-replication complex assembly is regulated by dynamic interplay between Fis, IHF and DnaA. Mol. Microbiol. 51: 1347-1359.