Moleculair Basis of Archaeal Physiology: The Bipolar Pyrimidine Operon and the Leucine/Lrp Regulon of Sulfolobus Acidocaldarius as Modelsystems for the Analysis of Mechanisms of Specific and Global Gene Regulation.

Archaea are true prokaryotes that constitute the third Domain of life. These microorganisms harbor the intriguing combination of a transcription apparatus that is typically eukaryotic whereas about molecular mechanism of archaeal transcription regulation, especially in thermophilic representatives. As model systems of archaeal transcrition regulation we propose to unravel the regulation of the bipolar pyrimidine operon and of the leucine/Lrp (Leucine responsive regulatory protein) regulon of the extreme thermoacidiphilic archaeon Sulfolobus acidocaldarius. Gene expression will be studied in vivo, and in vitro, regulatory olecules will be identified and characterized, protein-DNA interactions will be analyzed, a physico-chemical analysis of the regulatory Lrp protein will be performed and its structure determined by X-ray crystallography.