Term Name:	phosphorelay sensor kinase activity
Synonyms:	two-component sensor activity, two-component sensor molecule, two-component system sensor activity
Definition:	Catalysis of the phosphorylation of a histidine residue in response to detection of an extracellular signal such as a chemical ligand or change in environment, to initiate a change in cell state or activity. The two-component sensor is a histidine kinase that autophosphorylates a histidine residue in its active site. The phosphate is then transferred to an aspartate residue in a downstream response regulator, to trigger a response.
Ontology:	GO: Molecular Function [GO:0000155]    QuickGO    AmiGO