title: Activation and inhibition of the receptor histidine kinase AgrC occurs through opposite helical transduction motions.
abstract: Staphylococcus aureus virulence is regulated when secreted autoinducing peptides (AIPs) are recognized by a membrane-bound receptor histidine kinase (RHK), AgrC. Some AIPs are agonists of virulence gene expression, while others are antagonists. It is unclear how AIP binding regulates AgrC activity. Here, we reconstitute an AgrC family member, AgrC-I, using nanometer-scale lipid bilayer discs. We show that AgrC-I requires membranes rich in anionic lipids to function. The agonist, AIP-I, binds AgrC-I noncooperatively in a 2:2 stoichiometry, while an antagonist ligand, AIP-II, functions as an inverse agonist of the kinase activity. We also demonstrate the kinase and sensor domains in AgrC are connected by a helical linker whose conformational state exercises rheostat-like control over the kinase activity. Binding of agonist or inverse-agonist peptides results in twisting of the linker in different directions. These two observations provide a view of the molecular motions triggered by ligand binding in an intact membrane-bound RHK.
authors.affiliation: Department of Chemistry, Princeton University, Frick Chemistry Building, Washington Road, Princeton, NJ 08544, USA; Graduate Program, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
authors.forename: Boyuan
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Princeton University, Frick Chemistry Building, Washington Road, Princeton, NJ 08544, USA.
authors.forename: Aishan
authors.initials: A
authors.lastname: Zhao
authors.affiliation: Skirball Institute, Department of Microbiology, NYU Medical Center, 540 First Avenue, New York, NY 10016, USA.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Novick
authors.affiliation: Department of Chemistry, Princeton University, Frick Chemistry Building, Washington Road, Princeton, NJ 08544, USA. Electronic address: muir@princeton.edu.
authors.forename: Tom W
authors.initials: TW
authors.lastname: Muir
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008024:Ligands; D008051:Lipid Bilayers / Q000737:chemistry*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013211:Staphylococcus aureus / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D014774:Virulence
chemical_list: C414532:AgrD protein, Staphylococcus; D001426:Bacterial Proteins; D008024:Ligands; D008051:Lipid Bilayers; D010456:Peptides, Cyclic; D010743:Phospholipids; D020033:Protein Isoforms; D011994:Recombinant Proteins; D011494:Protein Kinases; C531166:AgrC protein, Staphylococcus