title: Protein histidine kinases: assembly of active sites and their regulation in signaling pathways.
abstract: Protein histidine kinases (PHKs) function in Two Component Signaling pathways utilized extensively by bacteria and archaea. Many PHKs participate in three distinct, but interrelated signaling reactions: autophoshorylation, phosphotransfer (to a partner Response Regulator (RR) protein), and dephosphorylation of this RR. Detailed biochemical and structural characterization of several PHKs has revealed how the domains of these proteins can interact to assemble the three active sites that promote the necessary chemistry and how these domain interactions might be regulated in response to sensory input: the relative orientation of helices in the PHK dimerization domain can reorient, via cogwheeling (rotation) and kinking (bending), to effect changes in PHK activities that probably involve sequestration/release of the PHK catalytic domain by the dimerization domain.
authors.affiliation: Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD 20742, USA. alec@umd.edu
authors.forename: Richard C
authors.initials: RC
authors.lastname: Stewart
mesh_terms: D001105:Archaea / Q000737:chemistry / Q000201:enzymology*; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism; D001419:Bacteria / Q000737:chemistry / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D020134:Catalytic Domain / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D000071677:Histidine Kinase; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction; D013329:Structure-Activity Relationship
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase