Bacillus subtilis and many other bacteria can be transformed by exogenous DNA when in a physiological state known as competence. Competent cells can bind DNA, fragment it on the cell surface and transport a single strand of DNA across the membrane. Once internalized, the single strand can integrate at a homologous site on the recipient chromosome. Our long-term objective is to understand these processes on the molecular level, by characterizing the 20 proteins involved and their interactions with one another and with DNA. We have shown that transformation takes place mostly at the cell poles. This proposal explores the interactions among many of the competence proteins, as well as their localization and delocalization as polar complexes. The recently discovered role of McsA and McsB in delocalization will be explored. We will also detect contacts between these proteins and DNA at various stages in the transformation process and determine the cellular addresses at which the contacts occur. The structure, composition and role of the competence pseudopilus will be explored. The sources of energy driving the transport of transforming DNA will be identified. Genetic screens will be used to find two competence proteins that have not been identified;the nuclease that degrades the non-transforming strand, and a second cell surface DNA binding protein. Transformation provides a mechanism for the horizontal transfer of antibiotic resistance and virulence genes among pathogens. Understanding the mechanism of gene transfer by transformation will provide insights into these important processes. Many bacteria can accept DNA from the environment in a process known as transformation. This provides a mechanism for the horizontal transfer of antibiotic resistance and virulence genes among pathogens. Understanding this process of gene transfer by transformation will provide insights into these important processes.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM043756-21
Application #
8025950
Study Section
Prokaryotic Cell and Molecular Biology Study Section (PCMB)
Program Officer
Deatherage, James F
Project Start
1990-12-01
Project End
2012-12-31
Budget Start
2011-01-01
Budget End
2012-12-31
Support Year
21
Fiscal Year
2011
Total Cost
$382,239
Indirect Cost
Name
University of Medicine & Dentistry of NJ
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
623946217
City
Newark
State
NJ
Country
United States
Zip Code
07107
Mann, Jessica M; Carabetta, Valerie J; Cristea, Ileana M et al. (2013) Complex formation and processing of the minor transformation pilins of Bacillus subtilis. Mol Microbiol 90:1201-15
Briley Jr, Kenneth; Dorsey-Oresto, Angella; Prepiak, Peter et al. (2011) The secretion ATPase ComGA is required for the binding and transport of transforming DNA. Mol Microbiol 81:818-30
Briley Jr, Kenneth; Prepiak, Peter; Dias, Miguel J et al. (2011) Maf acts downstream of ComGA to arrest cell division in competent cells of B. subtilis. Mol Microbiol 81:23-39
Burton, Briana; Dubnau, David (2010) Membrane-associated DNA transport machines. Cold Spring Harb Perspect Biol 2:a000406
Dubnau, David (2010) Swim or chill: lifestyles of a bacillus. Genes Dev 24:735-7
Johnsen, P J; Dubnau, D; Levin, B R (2009) Episodic selection and the maintenance of competence and natural transformation in Bacillus subtilis. Genetics 181:1521-33
Kramer, Naomi; Hahn, Jeanette; Dubnau, David (2007) Multiple interactions among the competence proteins of Bacillus subtilis. Mol Microbiol 65:454-64
Chen, Ines; Provvedi, Roberta; Dubnau, David (2006) A macromolecular complex formed by a pilin-like protein in competent Bacillus subtilis. J Biol Chem 281:21720-7
Draskovic, Irena; Dubnau, David (2005) Biogenesis of a putative channel protein, ComEC, required for DNA uptake: membrane topology, oligomerization and formation of disulphide bonds. Mol Microbiol 55:881-96
Chen, Ines; Christie, Peter J; Dubnau, David (2005) The ins and outs of DNA transfer in bacteria. Science 310:1456-60

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