Biology and Genetics of Prokaryotes
Archaea form one of three domains of life, in addition to bacteria and eukaryotes. The existence of this third domain of life was discovered only 1977, and accordingly Archaea are less well studied than the other two domains. Archaea exhibit a striking adaptive capability and can thrive in extremely varied habitats around the world, including environments characterized by extremes of temperature, pH-value, or pressure. Their metabolic capacity includes aerobic and anaerobic respiration, methanogenesis, fermentation as well as photosynthesis.
Professor Jörg Soppa uses these prokaryotes (cells without a eukaryotic nucleus) for basic research with an emphasis on molecular genetic and biochemical approaches. He concentrates especially on halophilic archaea, which grow in extremely saline environments that are found around the world. His research team analyses the adaptation of haloarchaea to various environmental conditions by means of differential gene expression. The different signal transduction chains as well as specific metabolic and transport capacities that are induced in response to external stimuli are of particular interest. The experimental approaches include the parallel quantification of all transcripts of the cell to gain a genome-wide insight into gene expression programmes. The analysis of the molecular mechanism of translation initiation led to an unexpected discovery. In approximately one third of all transcripts, translation is initiated using a "novel mechanism", which is distinct from the four previously known initiation mechanisms. Soppa's current objectives are to clarify the molecular details of this novel mechanism, to analyze the mechanism of translational control and to characterize the biological functions of small, non-coding regulatory RNAs (sRNAs) in the haloarchaea.
Another breakthrough result of Soppa's group was the discovery that the majority of archaeal and bacterial species do not contain only one copy of their chromosome, but harbours several or many copies and are thus oligoploid or polyploid. These results will correct the current textbook view that prokaryotes are monoploid. Future research is targeted toward understanding the different evolutionary advantages that have led to the selection of polyploid archaea and bacteria in various phylogenetic lineages and to elucidate the molecular mechanisms that control genome copy numbers, which in many species are tightly regulated in response to growth rate, growth phase, or environmental conditions.
After studying Biochemistry in Tübingen, Jörg Soppa completed his doctorate at the Max Planck Institute for Biochemistry in Martinsried near Munich. Starting in 1990 he established his own research group and gave microbiology courses at the Institute of Genetics and Microbiology of the University of Munich. There he received his Habilitation in 1994 and a year later he was awarded a Heisenberg grant (Heisenbergstipendium) by the German Research Foundation (DFG). After a short period as a guest scientist at the University of Vancouver, Canada, he moved his research group to the Institute of Microbiology at the Goethe University in Frankfurt, where he was appointed professor for microbial genetics in 2001. He coordinated the DFG Priority Programme "Genome function and gene regulation in Archaea" for seven years. Over the past ten years he has been active in various commissions at the Faculty of Biological Sciences, where he was dean of studies for nearly four years, and since 2007 he has been a member of the Senate's Commission for Equal Opportunities for Women.
Prof. Dr. Jörg Soppa
Institute of Molecular Biological Sciences
60438 Frankfurt am Main
Telephone: +49 (0)69 798 29564