PDBsum entry: 2ch7

Chemotaxis

PDB id: 2ch7

Contents

Protein chains

309 a.a. *

Metals

_PB ×2

Waters ×584

* Residue conservation analysis

PDB id:

2ch7

Name:

Chemotaxis

Title:

Crystal structure of the cytoplasmic domain of a bacterial chemoreceptor from thermotoga maritima

Structure:

Methyl-accepting chemotaxis protein. Chain: a. Fragment: cytoplasmic domain, residues 225-529. Synonym: methyl-accepting receptor mcp1143. Engineered: yes. Methyl-accepting chemotaxis protein. Chain: b. Fragment: cytoplasmic domain, residues 225-529. Synonym: methyl-accepting receptor mcp1143.

Source:

Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Biol. unit:

Dimer (from PDB file)

Resolution:

2.5Å R-factor: 0.258 R-free: 0.297

Authors:

S.Y.Park,A.M.Bilwes,B.R.Crane

Key ref:

S.Y.Park et al. (2006). Reconstruction of the chemotaxis receptor-kinase assembly. Nat Struct Mol Biol, 13, 400-407. PubMed id: 16622408 DOI: 10.1038/nsmb1085

Date:

13-Mar-06 Release date: 18-Apr-06

Protein chains

Q9X0M7  (MCP2_THEMA) -  Methyl-accepting chemotaxis protein 2

Seq: 530 a.a.

Struc: 309 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 

• Cellular component: membrane (1 term)
• Biological process: signal transduction (2 terms)
• Biochemical function: signal transducer activity (1 term)

DOI no: 10.1038/nsmb1085

Nat Struct Mol Biol 13:400-407 (2006)

PubMed id: 16622408

Reconstruction of the chemotaxis receptor-kinase assembly.

S.Y.Park, P.P.Borbat, G.Gonzalez-Bonet, J.Bhatnagar, A.M.Pollard, J.H.Freed, A.M.Bilwes, B.R.Crane.

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.

Selected figure(s)

Figure 2.
Figure 2. Pulsed ESR for reconstructing protein-protein complexes.

Figure 3.
Figure 3. CheW-CheA interactions. (a) CheW-P5 interaction determined by the pulsed-ESR experiment. Distances between spin labels (black asterisks) predict that CheW subdomain-2 (shown as NMR solution structure) binds the P5 proximal -barrel (from CheA 289 crystal structure). (b) Crystal structure of the CheA 354–CheW B conformation with secondary structure showing the topological equivalence of P5 and CheW. The proximal -barrel of P5 (subdomain-1) binds subdomain-2 of CheW. Residues essential for linking the CheA–CheW complex to MCP receptors in E. coli reside on the loop connecting the two P5 -barrels (magenta asterisks)^24, ^31. (c) The crystal structure of CheW bound to CheA domains P4 and P5. Two molecules of CheA 354–CheW in the asymmetric unit (conformations A and B) have different orientations of P4 (gray ribbons, with ADPNP shown in stick representation) relative to P5 (blue ribbons), although CheW (green ribbons) binds P5 the same way for both complexes.

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Mol Biol (2006, 13, 400-407) copyright 2006.

Figures were selected by the author.