Database accession: MF7000924
Name: Aer2 poly-HAMP domains: V33G HAMP1 inverted signaling mutant
PDB ID: 4i44
Experimental method: X-ray (2.88 Å)
Assembly: Homodimer
Source organism: Pseudomonas aeruginosa
Primary publication of the structure:
Airola MV, Sukomon N, Samanta D, Borbat PP, Freed JH, Watts KJ, Crane BR
HAMP domain conformers that propagate opposite signals in bacterial chemoreceptors.
(2013) PLoS Biol. 11: e1001479
PMID: 23424282
Abstract:
HAMP domains are signal relay modules in >26,000 receptors of bacteria, eukaryotes, and archaea that mediate processes involved in chemotaxis, pathogenesis, and biofilm formation. We identify two HAMP conformations distinguished by a four- to two-helix packing transition at the C-termini that send opposing signals in bacterial chemoreceptors. Crystal structures of signal-locked mutants establish the observed structure-to-function relationships. Pulsed dipolar electron spin resonance spectroscopy of spin-labeled soluble receptors active in cells verify that the crystallographically defined HAMP conformers are maintained in the receptors and influence the structure and activity of downstream domains accordingly. Mutation of HR2, a key residue for setting the HAMP conformation and generating an inhibitory signal, shifts HAMP structure and receptor output to an activating state. Another HR2 variant displays an inverted response with respect to ligand and demonstrates the fine energetic balance between "on" and "off" conformers. A DExG motif found in membrane proximal HAMP domains is shown to be critical for responses to extracellular ligand. Our findings directly correlate in vivo signaling with HAMP structure, stability, and dynamics to establish a comprehensive model for HAMP-mediated signal relay that consolidates existing views on how conformational signals propagate in receptors. Moreover, we have developed a rational means to manipulate HAMP structure and function that may prove useful in the engineering of bacterial taxis responses.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
identical protein binding identical protein binding
metal ion binding metal ion binding
transmembrane signaling receptor activity transmembrane signaling receptor activity
Biological process:
aerotaxis aerotaxis
chemotaxis chemotaxis
positive aerotaxis positive aerotaxis
signal transduction signal transduction
Cellular component:
cytoplasm cytoplasm
plasma membrane plasma membrane
Structural annotations of the participating protein chains.Entry contents: 2 distinct polypeptide molecules
Chains: A, A-2
Notes: All chains according to the most probable oligomerization state stored in PDBe were considered.
Number of unique protein segments: 1
Name: Methyl-accepting chemotaxis protein McpB
Source organism: Pseudomonas aeruginosa
Length: 679 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMGLFNAHAVAQQRADRIATLLQSFADGQLDTAVGEAPAPGYERLYDSLRALQRQLREQRAELQQVESLEAGLAEMSRQHEAGWIDQTIPAERLEGRAARIAKGVNELVAAHIAVKMKVVSVVTAYGQGNFEPLMDRLPGKKAQITEAIDGVRERLRGAAEATSAQLATAAYNARIKSALDNVSANVMIADNDLNIIYMNRTVSEMLGRAEADIRKQLPNFDAGRLMGANIDVFHKNPAHQRHLLANLTGVHKAELNLGGRRFSLDVVPVFNDANERLGSAVQWTDRTEEHRAEQEVSQLVQAAAAGDFSKRVEEAGKEGFFLRLAKDLNSLVDTADRGLRDVSRMLGALAQGDLTQRIEADYQGTFGQLKDFSNDTAQSLSRMLGQIREAADTINTAASEIASGNAELSARTEQQASSLEETASSMEELTSTVKLNAENARQANSLAANASEVATQGGTVVQKVVSTMSSINESARKIADIIGVIDGIAFQTNILALNAAVEAARAGEQGRGFAVVAGEVRTLAQRSAAAAKEIKTLISDSVDKVENGNTLVAQAGQTMSDIVVAIRRVTDIMSEIAAASAEQSTGIEEVNSAVSQMDDMTQQNAALVEEAAAAAEAMQEQAGLLNQSVAVFRLDTPPSVVQLASARPSAPRPSAPAPLARSGMARASKARKEDGWEEF
UniProtKB AC: Q9I6V6 (positions: 1-157)
Coverage: 23%
Name: Methyl-accepting chemotaxis protein McpB
Source organism: Pseudomonas aeruginosa
Length: 679 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMGLFNAHAVAQQRADRIATLLQSFADGQLDTAVGEAPAPGYERLYDSLRALQRQLREQRAELQQVESLEAGLAEMSRQHEAGWIDQTIPAERLEGRAARIAKGVNELVAAHIAVKMKVVSVVTAYGQGNFEPLMDRLPGKKAQITEAIDGVRERLRGAAEATSAQLATAAYNARIKSALDNVSANVMIADNDLNIIYMNRTVSEMLGRAEADIRKQLPNFDAGRLMGANIDVFHKNPAHQRHLLANLTGVHKAELNLGGRRFSLDVVPVFNDANERLGSAVQWTDRTEEHRAEQEVSQLVQAAAAGDFSKRVEEAGKEGFFLRLAKDLNSLVDTADRGLRDVSRMLGALAQGDLTQRIEADYQGTFGQLKDFSNDTAQSLSRMLGQIREAADTINTAASEIASGNAELSARTEQQASSLEETASSMEELTSTVKLNAENARQANSLAANASEVATQGGTVVQKVVSTMSSINESARKIADIIGVIDGIAFQTNILALNAAVEAARAGEQGRGFAVVAGEVRTLAQRSAAAAKEIKTLISDSVDKVENGNTLVAQAGQTMSDIVVAIRRVTDIMSEIAAASAEQSTGIEEVNSAVSQMDDMTQQNAALVEEAAAAAEAMQEQAGLLNQSVAVFRLDTPPSVVQLASARPSAPRPSAPAPLARSGMARASKARKEDGWEEF
UniProtKB AC: Q9I6V6 (positions: 1-157)
Coverage: 23%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: Methyl-accepting chemotaxis protein McpB, HAMP domains
Evidence level: Indirect evidence
Evidence coverage: The full structure participates in mutual synergistic folding.
Complex Evidence:
Aer2 1–172 is a symmetric dimer containing three HAMP domains. The basic construction unit of each HAMP domain is a monomeric unit of two parallel α-helices joined by a linker. This unit dimerizes and coils around a central supercoil axis to form a parallel four-helix bundle. The second and third HAMP domains are concatenated to form an interwoven di-HAMP structure (PMID:20399181).
Chain A:
N/A
Chain A-2:
N/A
Surface and contacts features:
Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap). Download the CIF file (.cif)
Download this entry's XML file (.xml)
Download this entry's JSON file (.json)
