Thursday, July 10, 2008

PhD student DNA Transport in Neisseria Gonorrhoeae, University of Groningen

Project description.
The rapid spread of antibiotic
resistance among bacteria is one of the major problems of the coming
century. This urges for an understanding of the mechanisms by which
antibiotic resistance is transmitted.

Conjugal DNA transport via type
IV secretion systems is one of the main causes responsible for this
spread, but little is known about the mechanism that governs conjugal
DNA transport. In Gram-negative bacteria, the DNA has to cross four
membranes, which makes it difficult to study DNA translocation by in vitro methods.

However, such studies will be
instrumental to reveal mechanistic features of this transport process.
Recently, an F factor conjugation-like DNA secretion system has been
described in pathogenic Neisseria gonorrhoea. Remarkably, this system
exports the DNA directly into the medium without the need for
cell-to-cell contact. Since here only two membranes have to be crossed,
this system is ideal to set up an in vitro DNA translocation system.
The aim is to reconstitute the DNA transport reaction both with inner
membrane vesicles and proteoliposomes reconstituted with purified
components. For this purpose, components of the DNA translocase will be
identified and overexpressed. Interactions between subunits of the DNA
translocase, located in the cytoplasm, inner membrane, periplasm and
outer membrane will be analyzed using immunoprecipitation,
co-purification, blue native electrophoresis, surface plasmon resonance
and further molecular biological, biochemical and biophysical

Offered position fellowship for a period of four years, which should lead to a PhD in Natural Sciences.

Required education/skills: University Graduate
For this project, I seek a highly motivated and skilled researcher with a masters degree in microbiology, biochemistry, molecular biology or similar.

The research will be conducted in the research group of Dr. Van der Does, which is embedded in the Department of Molecular Microbiology headed by Prof. A.J.M. Driessen. The department participates in the Groningen Biomolecular Sciences and
Biotechnology Institute (GBB) and the Material Sciences Center (MSCplus), a center of excellence. Further research is focused on the molecular mechanisms of bacterial protein export, membrane protein integration and solute transport, specifically multidrug and antibiotic transporters in bacteria, archaea and lower eukaryotes.

The emphasis is on the energetics and kinetics of the translocation processes, the
structural analysis of the proteins, and the role of transport processes in the physiology of micro-organisms. The laboratory is very well equipped, including molecular biology and protein purification (AKTA and FPLC) and analysis equipment e.g., large scale fermentation and centrifugation facilities, continuous cell lysis, (time-resolved) spectrofluorimeters, a Lumi-Imager, ultracentrifuges, and a fully equipped isotope laboratory.

Via GBB, there is direct access to various mass spectrometry techniques (Maldi-Tof, nanoLC-MS, ESI MS), DNA array and crystallography facilities, differential scanning and isothermal titration calorimetry, circular dichroism, time-resolved fluorescence spectroscopy and analytical ultracentrifugation. The group comprises a full, an associate and an assistant professor, 5 post-docs, 15 PhD students, and 5 technicians, and has been evaluated excellent by the last two VSNU quality assessment committees on all criteria. The group participates in three major Dutch technology innovation research networks, i.e., on proteomics, nanotechnology and on industrial micro-organisms.

During the years, the group has participated in many
EC programes, and more recently participates in an EC Human Mobility training network on molecular machines which involves leading groups in the
study of protein secretion and type II-IV secretion systems, and the EC
framework 6 program on the structural genomics of membrane proteins.
Intense links exist with industry, i.e., DSM (Anti-infectives, Delft ),
Biomade ( Groningen ), and Arpida Ltd ( Muenchenstein, Switserland).

Conditions of employment
The PhD student works as on a fellowship of 1390 Euro’s a month. Income
tax depends on the personal situation of the PhD student but generally
does not exceed 3% for this fellowship. These
positions are currently only available for non-Dutch nationals. The
appointment is for a period of four years and the work should lead to a
PhD in Natural Sciences.

Further information
About the vacancy: Dr. Chris van der does (e-mail :

Application (preferably by e-mail) should be send to:
Dr. Chris van der Does
University of Groningen
Department of Molecular Microbiology
Kerklaan 30
9751 NN Groningen
The Netherlands