Two-component systems comprising sensor histidine kinases and response regulator proteins are among the most important players in bacterial and archaeal signal transduction and also occur in reduced numbers in some eukaryotic organisms. Given their importance to cellular survival, virulence and cellular development these systems are among the most scrutinized bacterial proteins. In recent years a flurry of bioinformatics, genetic, biochemical and structural studies have provided detailed insights into many of the molecular mechanisms that underlie the detection of signals and the generation of the appropriate response by two-component systems. Importantly, it has become clear that there is significant diversity in the mechanisms employed by individual systems. This review discusses the current knowledge on common themes and divergences from the paradigm of two-component system signaling. An emphasis is on the information gained by a flurry of recent structural and bioinformatics studies.

Genome annotation and access to information from large-scale experimental approaches at the genome level are essential to improve our understanding of living cells and organisms. This is even more the case for model organisms that are the basis to study pathogens and technologically important species. We have generated SubtiWiki, a database for the Gram-positive model bacterium Bacillus subtilis (http://subtiwiki.uni-goettingen.de/). In addition to the established companion modules of SubtiWiki, SubtiPathways and SubtInteract, we have now created SubtiExpress, a third module, to visualize genome scale transcription data that are of unprecedented quality and density. Today, SubtiWiki is one of the most complete collections of knowledge on a living organism in one single resource.

EIIANtr is a member of a truncated phosphotransferase (PTS) system that serves regulatory functions and exists in many Proteobacteria in addition to the sugar transport PTS.

The emergence of multi-drug-resistant bacteria emphasizes the urgent need for novel antibacterial compounds targeting unique cellular processes. Two-component signal transduction systems (TCSs) are commonly used by bacteria to couple environmental stimuli to adaptive responses, are absent in mammals, and are embedded in various pathogenic pathways. To attenuate these signaling pathways, we aimed to target the TCS signal transducer histidine kinase (HK) by focusing on their highly conserved adenosine triphosphate (ATP)-binding domain. We used a structure-based drug design strategy to identify new inhibitors of bacterial HKs. Thus, ligands were designed, leading to a series of thiophene derivatives. These compounds were synthesized and evaluated in vitro against bacterial HKs. We identified eight compounds with significant inhibitory activities against these proteins, two of which exhibited broad-spectrum antimicrobial