4JPB

The structure of a ternary complex between CheA domains P4 and P5 with CheW and with an unzipped fragment of TM14, a chemoreceptor analog from Thermotoga maritima.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.19 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.198 

wwPDB Validation 3D Report Full Report



Literature

The 3.2 angstrom resolution structure of a receptor: CheA:CheW signaling complex defines overlapping binding sites and key residue interactions within bacterial chemosensory arrays.

Li, X.Fleetwood, A.D.Bayas, C.Bilwes, A.M.Ortega, D.R.Falke, J.J.Zhulin, I.B.Crane, B.R.

(2013) Biochemistry 52: 3852-3865

  • DOI: 10.1021/bi400383e
  • Primary Citation of Related Structures:  
    4JPB

  • PubMed Abstract: 
  • Bacterial chemosensory arrays are composed of extended networks of chemoreceptors (also known as methyl-accepting chemotaxis proteins, MCPs), the histidine kinase CheA, and the adaptor protein CheW. Models of these arrays have been developed from cry ...

    Bacterial chemosensory arrays are composed of extended networks of chemoreceptors (also known as methyl-accepting chemotaxis proteins, MCPs), the histidine kinase CheA, and the adaptor protein CheW. Models of these arrays have been developed from cryoelectron microscopy, crystal structures of binary and ternary complexes, NMR spectroscopy, mutational, data and biochemical studies. A new 3.2 Å resolution crystal structure of a Thermotoga maritima MCP protein interaction region in complex with the CheA kinase-regulatory module (P4-P5) and adaptor protein CheW provides sufficient detail to define residue contacts at the interfaces formed among the three proteins. As in a previous 4.5 Å resolution structure, CheA-P5 and CheW interact through conserved hydrophobic surfaces at the ends of their β-barrels to form pseudo 6-fold symmetric rings in which the two proteins alternate around the circumference. The interface between P5 subdomain 1 and CheW subdomain 2 was anticipated from previous studies, whereas the related interface between CheW subdomain 1 and P5 subdomain 2 has only been observed in these ring assemblies. The receptor forms an unexpected structure in that the helical hairpin tip of each subunit has "unzipped" into a continuous α-helix; four such helices associate into a bundle, and the tetramers bridge adjacent P5-CheW rings in the lattice through interactions with both P5 and CheW. P5 and CheW each bind a receptor helix with a groove of conserved hydrophobic residues between subdomains 1 and 2. P5 binds the receptor helix N-terminal to the tip region (lower site), whereas CheW binds the same helix with inverted polarity near the bundle end (upper site). Sequence comparisons among different evolutionary classes of chemotaxis proteins show that the binding partners undergo correlated changes at key residue positions that involve the lower site. Such evolutionary analyses argue that both CheW and P5 bind to the receptor tip at overlapping positions. Computational genomics further reveal that two distinct CheW proteins in Thermotogae utilize the analogous recognition motifs to couple different receptor classes to the same CheA kinase. Important residues for function previously identified by mutagenesis, chemical modification and biophysical approaches also map to these same interfaces. Thus, although the native CheW-receptor interaction is not observed in the present crystal structure, the bioinformatics and previous data predict key features of this interface. The companion study of the P5-receptor interface in native arrays (accompanying paper Piasta et al. (2013) Biochemistry, DOI: 10.1021/bi400385c) shows that, despite the non-native receptor fold in the present crystal structure, the local helix-in-groove contacts of the crystallographic P5-receptor interaction are present in native arrays and are essential for receptor regulation of kinase activity.


    Organizational Affiliation

    Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Chemotaxis protein CheAA319Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: cheATM_0702
EC: 2.7.13.3
Find proteins for Q56310 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Explore Q56310 
Go to UniProtKB:  Q56310
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Chemotaxis protein CheWW151Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: cheWTM_0701
Find proteins for Q56311 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Explore Q56311 
Go to UniProtKB:  Q56311
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Methyl-accepting chemotaxis proteinBC90Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: ThemaDRAFT_1422Tm00014TM_0014
Find proteins for Q7DFA3 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Explore Q7DFA3 
Go to UniProtKB:  Q7DFA3
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.19 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.198 
  • Space Group: H 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 213.588α = 90
b = 213.588β = 90
c = 208.838γ = 120
Software Package:
Software NamePurpose
ADSCdata collection
PHASERphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-08-28
    Type: Initial release