Project description.The rapid spread of antibioticresistance among bacteria is one of the major problems of the comingcentury. This urges for an understanding of the mechanisms by whichantibiotic resistance is transmitted. Conjugal DNA transport via typeIV secretion systems is one of the main causes responsible for thisspread, but little is known about the mechanism that governs conjugalDNA transport. In Gram-negative bacteria, the DNA has to cross fourmembranes, which makes it difficult to study DNA translocation by in vitro methods. However, such studies will beinstrumental to reveal mechanistic features of this transport process.Recently, an F factor conjugation-like DNA secretion system has beendescribed in pathogenic Neisseria gonorrhoea. Remarkably, this systemexports the DNA directly into the medium without the need forcell-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 innermembrane vesicles and proteoliposomes reconstituted with purifiedcomponents. For this purpose, components of the DNA translocase will beidentified and overexpressed. Interactions between subunits of the DNAtranslocase, located in the cytoplasm, inner membrane, periplasm andouter membrane will be analyzed using immunoprecipitation,co-purification, blue native electrophoresis, surface plasmon resonanceand further molecular biological, biochemical and biophysicaltechniques.
Offered positionfellowship for a period of four years, which should lead to a PhD in Natural Sciences.
RequirementsRequired education/skills: University GraduateFor this project, I seek a highly motivated and skilled researcher with a masters degree in microbiology, biochemistry, molecular biology or similar.
OrganizationThe research will be conducted in theresearch group of Dr. Van der Does, which is embedded in the Departmentof Molecular Microbiology headed by Prof. A.J.M. Driessen. Thedepartment participates in the Groningen Biomolecular Sciences andBiotechnology Institute (GBB) and the Material Sciences Center(MSCplus), a center of excellence. Further research is focused on themolecular mechanisms of bacterial protein export, membrane proteinintegration and solute transport, specifically multidrug and antibiotictransporters in bacteria, archaea and lower eukaryotes. The emphasis ison the energetics and kinetics of the translocation processes, thestructural analysis of the proteins, and the role of transportprocesses in the physiology of micro-organisms. The laboratory is verywell equipped, including molecular biology and protein purification(AKTA and FPLC) and analysis equipment e.g., large scale fermentationand centrifugation facilities, continuous cell lysis, (time-resolved)spectrofluorimeters, a Lumi-Imager, ultracentrifuges, and a fullyequipped isotope laboratory. Via GBB, there is direct access to variousmass spectrometry techniques (Maldi-Tof, nanoLC-MS, ESI MS), DNA arrayand crystallography facilities, differential scanning and isothermaltitration calorimetry, circular dichroism, time-resolved fluorescencespectroscopy and analytical ultracentrifugation. The group comprises afull, an associate and an assistant professor, 5 post-docs, 15 PhDstudents, and 5 technicians, and has been evaluated excellent by thelast two VSNU quality assessment committees on all criteria. The groupparticipates in three major Dutch technology innovation researchnetworks, i.e., on proteomics, nanotechnology and on industrialmicro-organisms. During the years, the group has participated in manyEC programes, and more recently participates in an EC Human Mobility training network on molecular machines which involves leading groups in thestudy of protein secretion and type II-IV secretion systems, and the ECframework 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. Incometax depends on the personal situation of the PhD student but generallydoes not exceed 3% for this fellowship. Thesepositions are currently only available for non-Dutch nationals. Theappointment is for a period of four years and the work should lead to aPhD in Natural Sciences.Further informationAbout the vacancy: Dr. Chris van der does (e-mail : c.van.der.does@rug.nl)Application (preferably by e-mail) should be send to:
Dr. Chris van der Does
University of Groningen
Department of Molecular Microbiology
Kerklaan 309751 NN Groningen
The Netherlands
e-mail: c.van.der.does@rug.nl
