title: Reconstruction of the chemotaxis receptor-kinase assembly.
abstract: In bacterial chemotaxis, an assembly of transmembrane receptors, the CheA histidine kinase and the adaptor protein CheW processes environmental stimuli to regulate motility. The structure of a Thermotoga maritima receptor cytoplasmic domain defines CheA interaction regions and metal ion-coordinating charge centers that undergo chemical modification to tune receptor response. Dimeric CheA-CheW, defined by crystallography and pulsed ESR, positions two CheWs to form a cleft that is lined with residues important for receptor interactions and sized to clamp one receptor dimer. CheW residues involved in kinase activation map to interfaces that orient the CheW clamps. CheA regulatory domains associate in crystals through conserved hydrophobic surfaces. Such CheA self-contacts align the CheW receptor clamps for binding receptor tips. Linking layers of ternary complexes with close-packed receptors generates a lattice with reasonable component ratios, cooperative interactions among receptors and accessible sites for modification enzymes.
authors.affiliation: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Sang-Youn
authors.initials: SY
authors.lastname: Park
authors.forename: Peter P
authors.initials: PP
authors.lastname: Borbat
authors.forename: Gabriela
authors.initials: G
authors.lastname: Gonzalez-Bonet
authors.forename: Jaya
authors.initials: J
authors.lastname: Bhatnagar
authors.forename: Abiola M
authors.initials: AM
authors.lastname: Pollard
authors.forename: Jack H
authors.initials: JH
authors.lastname: Freed
authors.forename: Alexandrine M
authors.initials: AM
authors.lastname: Bilwes
authors.forename: Brian R
authors.initials: BR
authors.lastname: Crane
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002633:Chemotaxis; D018360:Crystallography, X-Ray; D003593:Cytoplasm / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019281:Dimerization; D004578:Electron Spin Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008958:Models, Molecular; D011485:Protein Binding; D017510:Protein Folding; D011494:Protein Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020836:Protein Structure, Quaternary; D015398:Signal Transduction; D020124:Thermotoga maritima / Q000166:cytology / Q000201:enzymology* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C051236:CheW protein, Bacteria; D011494:Protein Kinases