Our long term goals are to understand the bacterial cell cycle and the connections among chromosome replication, organization, partitioning, and gene expression. Cell growth, propagation, and development all require the duplication and faithful segregation of chromosomal DNA. To ensure that these essential processes are proceeding normally, cells possess regulatory mechanisms that couple division or development to the fidelity of chromosomal transmission. Many diseases, including cancers, result from aberrant regulation of the cell cycle and loss of fidelity of chromosome transmission. In addition, microbial pathogenesis often depends on normal bacterial growth in the host. This proposal focuses on several aspects of the Bacillus subtilis cell cycle with three areas of particular interest related to chromosome dynamics and gene expression: 1) the regulatory response to arrest of replication forks; 2) initiation of replication and the subcellular positioning of oriC and the replisome; and 3) proteins and DNA sites involved in chromosome compaction and cohesion and their effects on gene expression. We will use a variety of approaches and methodologies to characterize: genes controlled in response to replication fork arrest; the role of DnaA, the replication initiator protein, in the transcriptional response to replication fork arrest; the subcellular positioning of the chromosomal origin of replication and its association with the membrane; the functions of two essential genes replication initiation genes; factors controlling replisome positioning in the cell; proteins involved in chromosome compaction and cohesion, and their roles in gene expression. The fundamental principles and mechanisms controlling these processes are easily studied in B. subtilis using a combination of cell biological, genetic, molecular, physiological, biochemical, and bioinformatic approaches. Because many of the proteins involved in these processes are highly conserved, insights gained from work with B. subtilis are likely to provide information regarding similar processes in a wide variety of organisms. Learning more about the essential mechanisms governing the chromosome replication and partitioning could lead to the identification of targets for the development of new antibiotics.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-MBC-2 (01))
Program Officer
Rhoades, Marcus M
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Massachusetts Institute of Technology
Schools of Arts and Sciences
United States
Zip Code
Seid, Charlotte A; Smith, Janet L; Grossman, Alan D (2017) Genetic and biochemical interactions between the bacterial replication initiator DnaA and the nucleoid-associated protein Rok in Bacillus subtilis. Mol Microbiol 103:798-817
Washington, Tracy A; Smith, Janet L; Grossman, Alan D (2017) Genetic networks controlled by the bacterial replication initiator and transcription factor DnaA in Bacillus subtilis. Mol Microbiol 106:109-128
Schons-Fonseca, Luciane; da Silva, Josefa B; Milanez, Juliana S et al. (2016) Analysis of LexA binding sites and transcriptomics in response to genotoxic stress in Leptospira interrogans. Nucleic Acids Res 44:1179-91
Smith, Janet L; Grossman, Alan D (2015) In Vitro Whole Genome DNA Binding Analysis of the Bacterial Replication Initiator and Transcription Factor DnaA. PLoS Genet 11:e1005258
Bonilla, Carla Y; Grossman, Alan D (2012) The primosomal protein DnaD inhibits cooperative DNA binding by the replication initiator DnaA in Bacillus subtilis. J Bacteriol 194:5110-7
Merrikh, Houra; Zhang, Yan; Grossman, Alan D et al. (2012) Replication-transcription conflicts in bacteria. Nat Rev Microbiol 10:449-58
Merrikh, Houra; Grossman, Alan D (2011) Control of the replication initiator DnaA by an anti-cooperativity factor. Mol Microbiol 82:434-46
Merrikh, Houra; Machón, Cristina; Grainger, William H et al. (2011) Co-directional replication-transcription conflicts lead to replication restart. Nature 470:554-7
Rahn-Lee, Lilah; Merrikh, Houra; Grossman, Alan D et al. (2011) The sporulation protein SirA inhibits the binding of DnaA to the origin of replication by contacting a patch of clustered amino acids. J Bacteriol 193:1302-7
Smits, Wiep Klaas; Merrikh, Houra; Bonilla, Carla Yaneth et al. (2011) Primosomal proteins DnaD and DnaB are recruited to chromosomal regions bound by DnaA in Bacillus subtilis. J Bacteriol 193:640-8

Showing the most recent 10 out of 81 publications