Taxonomic distribution of proteins containing CHASE2 domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing CHASE2 domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

Common extracellular sensory domains in transmembrane receptors fordiverse signal transduction pathways in bacteria and archaea.

Zhulin IB, Nikolskaya AN, Galperin MY
J Bacteriol. 2003; 185: 285-94

Transmembrane receptors in microorganisms, such as sensory histidinekinases and methyl-accepting chemotaxis proteins, are molecular devicesfor monitoring environmental changes. We report here that sensory domainsharing is widespread among different classes of transmembrane receptors.We have identified two novel conserved extracellular sensory domains,named CHASE2 and CHASE3, that are found in at least four classes oftransmembrane receptors: histidine kinases, adenylate cyclases, predicteddiguanylate cyclases, and either serine/threonine protein kinases (CHASE2)or methyl-accepting chemotaxis proteins (CHASE3). Three otherextracellular sensory domains were shared by at least two differentclasses of transmembrane receptors: histidine kinases and eitherdiguanylate cyclases, adenylate cyclases, or phosphodiesterases. Theseobservations suggest that microorganisms use similar conserved domains tosense similar environmental signals and transmit this information viadifferent signal transduction pathways to different regulatory circuits:transcriptional regulation (histidine kinases), chemotaxis(methyl-accepting proteins), catabolite repression (adenylate cyclases),and modulation of enzyme activity (diguanylate cyclases andphosphodiesterases). The variety of signaling pathways using theCHASE-type domains indicates that these domains sense some criticallyimportant extracellular signals.