REGULATED GENE-EXPRESSION IN METHANOGENS

Methanogens form a very large and diverse group of microorganisms with in the domain of the Archaea. Energy for their growth is obtained by t he reduction of a variety of substrates into methane. Several genes, c oding for enzymes involved in methanogenesis or in the central metabol ism have been cloned and studied. The molecular features of their expr ession signals have been compared with bacterial and eukaryal expressi on signals. This indicated that the transcription process is an interm ediate form between the specific processes known in Bacteria and Eukar ya. The translation system that is used in Archaea is very similar wit h the process in Bacteria. Although the molecular features of genes an d expression signals in Archaea are well-studied, investigations on th e regulation of gene expression in these organisms are very scarce. In order to give insight into molecular regulatory mechanisms in methano gens, the current knowledge of regulated systems in methanogens will b e reviewed in this manuscript.