Bacterial single-strand (ss) DNA-binding proteins (SSBs) play essential protective and organizational roles in genome biology. To shield ssDNA from potential damage, multiple SSBs assemble into """"""""nucleosome-like"""""""" scaffolds, the structures of which are not well understood. Far from being inert, ssDNA/SSB complexes are active DNA processing centers where at least a dozen different enzymes gain access to genomic substrates by exploiting direct protein-protein interactions with SSB. In all cases examined to date, SSB's flexible C-terminus (SSB-Ct) forms a docking site for heterologous proteins. How proteins bind to the SSB-Ct sequence and how these essential interactions affect the activities of genome maintenance enzymes remains poorly defined. Given the importance of SSB's interactions with heterologous proteins, inhibitors that block formation of these SSB protein complexes have great potential as novel anti-bacterial agents. The ultimate goals of this proposal are to elucidate the structures of ssDNA/SSB substrates, to reveal how enzymes take advantage of direct binding to SSB to process these structures, and to characterize the anti-bacterial properties of inhibitors that block heterologous protein association with SSB. The proposal brings together biochemical, structural, and genetic approaches to address these questions.

Public Health Relevance

Genome maintenance processes ensure the accuracy of genetic information in cells and provide mechanisms whereby this information can be faithfully duplicated and distributed to daughter cells. These are essential process for all cells and require precise coordinate of many different proteins. This proposal aims to understand how several of these protein components are coordinated in cells and to investigate the anti-bacterial mechanisms of inhibitors that selectively block this coordination in bacteria.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Prokaryotic Cell and Molecular Biology Study Section (PCMB)
Program Officer
Jones, Warren
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Wisconsin Madison
Schools of Medicine
United States
Zip Code
Marceau, Aimee H; Bernstein, Douglas A; Walsh, Brian W et al. (2013) Protein interactions in genome maintenance as novel antibacterial targets. PLoS One 8:e58765
Manthei, Kelly A; Keck, James L (2013) The BLM dissolvasome in DNA replication and repair. Cell Mol Life Sci 70:4067-84
Norais, C├ędric; Servant, Pascale; Bouthier-de-la-Tour, Claire et al. (2013) The Deinococcus radiodurans DR1245 protein, a DdrB partner homologous to YbjN proteins and reminiscent of type III secretion system chaperones. PLoS One 8:e56558
Cahoon, Laty A; Manthei, Kelly A; Rotman, Ella et al. (2013) Neisseria gonorrhoeae RecQ helicase HRDC domains are essential for efficient binding and unwinding of the pilE guanine quartet structure required for pilin antigenic variation. J Bacteriol 195:2255-61
George, Nicholas P; Ngo, Khanh V; Chitteni-Pattu, Sindhu et al. (2012) Structure and cellular dynamics of Deinococcus radiodurans single-stranded DNA (ssDNA)-binding protein (SSB)-DNA complexes. J Biol Chem 287:22123-32
Hoadley, Kelly A; Xue, Yutong; Ling, Chen et al. (2012) Defining the molecular interface that connects the Fanconi anemia protein FANCM to the Bloom syndrome dissolvasome. Proc Natl Acad Sci U S A 109:4437-42
Marceau, Aimee H; Bahng, Soon; Massoni, Shawn C et al. (2011) Structure of the SSB-DNA polymerase III interface and its role in DNA replication. EMBO J 30:4236-47
Lindner, Scott E; Llinas, Manuel; Keck, James L et al. (2011) The primase domain of PfPrex is a proteolytically matured, essential enzyme of the apicoplast. Mol Biochem Parasitol 180:69-75
Page, Asher N; George, Nicholas P; Marceau, Aimee H et al. (2011) Structure and biochemical activities of Escherichia coli MgsA. J Biol Chem 286:12075-85
Lu, Duo; Myers, Angela R; George, Nicholas P et al. (2011) Mechanism of Exonuclease I stimulation by the single-stranded DNA-binding protein. Nucleic Acids Res 39:6536-45

Showing the most recent 10 out of 31 publications