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Molecular Biology Research Group,
Chair of Molecular and Cellular Biology,
Intercollegiate Faculty of Biotechnology,
University of Gdańsk
Head: Dr Igor Konieczny
Associate Professor
igor@biotech.ug.gda.pl
phone: +48 58 301 2241 ext. 365
fax: +48 58 301 9222
Broad-host-range plasmid DNA replication
PREVIOUS AND CURRENT RESEARCH, FUTURE GOALS
Most bacteria contain plasmids, which are circular DNA physically separate from the chromosome. Plasmids play a major role in horizontal gene transfer among bacteria. During this process, plasmids can confer a number of valuable traits upon the host organism, including resistance to antibiotics and heavy metals, production of toxins, and degradation of toxic compounds. Studies on plasmid transfer and plasmid host specificity can add to our understanding of fundamental processes such as DNA replication, chaperone protein activities and regulated proteolysis. The insights obtained from these investigations may result in new tools for fighting pathogens.
Majority of plasmids are stably maintained in their natural host only. In contrast, promiscuous plasmids including plasmid RK2 are adapted to replicate and be stable in diverse groups of bacteria including plant, animal and human pathogens. These plasmids are ideal models to study the host specificity of fundamental cellular processes. Previously others and we have been analyzing plasmid metabolism mainly in one bacterium, Escherichia coli.
Our goals are directed towards understanding the genetic and biochemical mechanisms responsible for the initiation and stable maintenance of plasmid DNA in distantly related bacteria. Investigations are carried out to describe the host specificity of the molecular mechanisms whereby replication of the RK2 plasmid is initiated. We want to determine and characterize host chaperone systems whereby the protein that initiates plasmid replication is activated. We are also interested in analyzing host-dependent proteolysis of plasmid factors and in describing the post-segregational killing system. The determination of how chaperones and proteolysis affect plasmid distribution and segregation is another of our goals.
SELECTED PUBLICATIONS
Caspi, R., Pacek, M., Consiglieri, G., Helinski, D., Toukdarian, A., Konieczny, I. (2001) A Broad-Host-Range Replicon with Different Requirements for Replication Initiation in Three Bacterial Species EMBO J. 20 (12) 3262-3271
Pacek, M., Konopa, G., Konieczny, I. (2001) DnaA-box Sequences as the Site for Helicase Delivery during Plasmid RK2 Replication Initiation in Escherichia coli J. Biol. Chem. 276, (26) 23639-23644
Konieczny, I., Liberek, K. (2002) Cooperative action of Escherichia coli ClpB protein and DnaK chaperone in the activation of a replication initiation protein. J. Biol. Chem., 277(21) 18483-8.
Konieczny I (2003) Strategies for helicase recruitment and loading in bacteria. EMBO Reports. 2003 (1) 37-41
Jiang Y, Pacek M, Helinski DR, Konieczny I, Toukdarian A. (2003) A multifunctional plasmid-encoded replication initiation protein both recruits and positions an active helicase at the replication origin. Proc. Natl. Acad. Sci. U. S. A.,100 (15) 8692-7
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Intercollegiate
Faculty of Biotechnology
UG-AMG
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Kładki st. 24
80-822 Gdańsk
POLAND
tel. (+48-58) 301-04-10
fax: 301-03-81
E-mail: dziekanat@biotech.ug.gda.pl |
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Biotechnology Summer School
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