title: Structure of PAS-linked histidine kinase and the response regulator complex.
abstract: We determined the structure of the complex of the sensory histidine kinase (HK) and its cognate response regulator (RR) in the two-component signal transduction system of Thermotoga maritima. This was accomplished by fitting the high-resolution structures of the isolated HK domains and the RR onto the electron density map (3.8 A resolution) of the HK/RR complex crystal. Based on the structural information, we evaluated the roles of both interdomain and intermolecular interactions in the signal transduction of the cytosolic PAS-linked HK and RR system, in particular the O(2)-sensor FixL/FixJ system. The PAS-sensor domain of HK interacts with the catalytic domain of the same polypeptide chain by creating an interdomain beta sheet. The interaction site between HK and RR, which was confirmed by NMR, is suitable for the intermolecular transfer reaction of the phosphoryl group, indicating that the observed interaction is important for the phosphatase activity of HK that dephosphorylates phospho-RR.
authors.affiliation: RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Yamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Miki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Ayako
authors.initials: A
authors.lastname: Ohno
authors.forename: Hiro
authors.initials: H
authors.lastname: Nakamura
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Shiro
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D000071677:Histidine Kinase; D008958:Models, Molecular; D011494:Protein Kinases / Q000737:chemistry* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry; D015398:Signal Transduction; D020124:Thermotoga maritima / Q000201:enzymology / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011494:Protein Kinases; C116037:PAS domain kinases; D017346:Protein Serine-Threonine Kinases; D000071677:Histidine Kinase