3G67
Crystal Structure of a Soluble Chemoreceptor from Thermotoga maritima
Summary for 3G67
| Entry DOI | 10.2210/pdb3g67/pdb |
| Related | 3G6B |
| Descriptor | Methyl-accepting chemotaxis protein (2 entities in total) |
| Functional Keywords | four-helix bundle, methyl-accepting chemotaxis protein, signaling protein |
| Biological source | Thermotoga maritima |
| Total number of polymer chains | 2 |
| Total formula weight | 48268.53 |
| Authors | Pollard, A.M.,Bilwes, A.M.,Crane, B.R. (deposition date: 2009-02-06, release date: 2009-07-28, Last modification date: 2024-02-21) |
| Primary citation | Pollard, A.M.,Bilwes, A.M.,Crane, B.R. The structure of a soluble chemoreceptor suggests a mechanism for propagating conformational signals. Biochemistry, 48:1936-1944, 2009 Cited by PubMed Abstract: Transmembrane chemoreceptors, also known as methyl-accepting chemotaxis proteins (MCPs), translate extracellular signals into intracellular responses in the bacterial chemotaxis system. MCP ligand binding domains control the activity of the CheA kinase, situated approximately 200 A away, across the cytoplasmic membrane. The 2.17 A resolution crystal structure of a Thermotoga maritima soluble receptor (Tm14) reveals distortions in its dimeric four-helix bundle that provide insight into the conformational states available to MCPs for propagating signals. A bulge in one helix generates asymmetry between subunits that displaces the kinase-interacting tip, which resides more than 100 A away. The maximum bundle distortion maps to the adaptation region of transmembrane MCPs where reversible methylation of acidic residues tunes receptor activity. Minor alterations in coiled-coil packing geometry translate the bulge distortion to a >25 A movement of the tip relative to the bundle stalks. The Tm14 structure discloses how alterations in local helical structure, which could be induced by changes in methylation state and/or by conformational signals from membrane proximal regions, can reposition a remote domain that interacts with the CheA kinase. PubMed: 19149470DOI: 10.1021/bi801727m PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.17 Å) |
Structure validation
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