Database accession: MF7000700
Name: Imp2 F-BAR domain
PDB ID: 5c1f
Experimental method: X-ray (2.36 Å)
Assembly: Homodimer
Source organism: Schizosaccharomyces pombe
Primary publication of the structure:
McDonald NA, Takizawa Y, Feoktistova A, Xu P, Ohi MD, Vander Kooi CW, Gould KL
The Tubulation Activity of a Fission Yeast F-BAR Protein Is Dispensable for Its Function in Cytokinesis.
(2016) Cell Rep 14: 534-546
PMID: 26776521
Abstract:
F-BAR proteins link cellular membranes to the actin cytoskeleton in many biological processes. Here we investigated the function of the Schizosaccharomyces pombe Imp2 F-BAR domain in cytokinesis and find that it is critical for Imp2's role in contractile ring constriction and disassembly. To understand mechanistically how the F-BAR domain functions, we determined its structure, elucidated how it interacts with membranes, and identified an interaction between dimers that allows helical oligomerization and membrane tubulation. Using mutations that block either membrane binding or tubulation, we find that membrane binding is required for Imp2's cytokinetic function but that oligomerization and tubulation, activities often deemed central to F-BAR protein function, are dispensable. Accordingly, F-BARs that do not have the capacity to tubulate membranes functionally substitute for the Imp2 F-BAR, establishing that its major role is as a cell-cycle-regulated bridge between the membrane and Imp2 protein partners, rather than as a driver of membrane curvature.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
cytoskeletal protein-membrane anchor activity cytoskeletal protein-membrane anchor activity
phosphatidylinositol-3,4,5-trisphosphate binding phosphatidylinositol-3,4,5-trisphosphate binding
phosphatidylinositol-4-phosphate binding phosphatidylinositol-4-phosphate binding
phosphatidylserine binding phosphatidylserine binding
phospholipid binding phospholipid binding
Biological process:
cytoskeleton organization cytoskeleton organization
mitotic actomyosin contractile ring assembly mitotic actomyosin contractile ring assembly
Cellular component:
actomyosin contractile ring actomyosin contractile ring
cell division site cell division site
cytoplasm cytoplasm
cytoplasmic side of plasma membrane cytoplasmic side of plasma membrane
cytosol cytosol
mitotic actomyosin contractile ring mitotic actomyosin contractile ring
mitotic actomyosin contractile ring, proximal layer mitotic actomyosin contractile ring, proximal layer
plasma membrane plasma membrane
Structural annotations of the participating protein chains.Entry contents: 2 distinct polypeptide molecules
Chains: A, B
Notes: All chains according to the most probable oligomerization state stored in PDBe were considered.
Number of unique protein segments: 1
Name: Septation protein imp2
Source organism: Schizosaccharomyces pombe
Length: 670 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSQQLSFNASSAKPDKSFSNYFWGANDEGYHALLSRFSDVKHINEELRSFYHERANIEEDYAKRMAKLSRTTFSSLETGCLKESVQVMKAEVDNMAKSHLQISQLLQDDVENAFTRYAASLKDKKKMIVSGIEKVHKDKLSKHQALVKAQDKYHYLCKKVNYYVSQQNMLFGKELEKNNAKLNKTQNAITASSSDYQSAVAAVRDSYARWTNEWRSTCDKLQDIEEERRHFLKSVMWTFTLLISRSCFNDDQACERIRKNLEQCSVSQDVLEFIDAKSTGTGIPQPPKFYDYYKGEVPDDSVELVQANFQRAQTKIENDNMPLNRPYVLSATARNESSFENTLPNTPSAIQSLTTVSSNSSQNGRSSPKKSFLSKFKLTSRPSTPNVGNTAPDALSSPRNDSPLTSAADEQMKHLSLQEEPKQNPTPAAPGAFPNSNTLPPRYNELGSLPSPNSVSFTEDSRPNVNTPSRRQQIQEEFGSVLQMENRAVSPVYDSRKNGSRSSFTLRKSRSPKRPSSSLSQNASRLPRSLTPGNLEPNYDFGVRVDPASGTAPTDDEPYTDRDSSFVDDTINTKATGNTSNRLSLPAYPTDGGDTSIDNPTSTDGQRILGYVSALYDYDAAIPEEISFRKGDTIAVLKLYEDGWWEGFVVGEDDHNRGQFPSNFVREIEV
UniProtKB AC: Q10199 (positions: 15-311)
Coverage: 44%
Name: Septation protein imp2
Source organism: Schizosaccharomyces pombe
Length: 670 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSQQLSFNASSAKPDKSFSNYFWGANDEGYHALLSRFSDVKHINEELRSFYHERANIEEDYAKRMAKLSRTTFSSLETGCLKESVQVMKAEVDNMAKSHLQISQLLQDDVENAFTRYAASLKDKKKMIVSGIEKVHKDKLSKHQALVKAQDKYHYLCKKVNYYVSQQNMLFGKELEKNNAKLNKTQNAITASSSDYQSAVAAVRDSYARWTNEWRSTCDKLQDIEEERRHFLKSVMWTFTLLISRSCFNDDQACERIRKNLEQCSVSQDVLEFIDAKSTGTGIPQPPKFYDYYKGEVPDDSVELVQANFQRAQTKIENDNMPLNRPYVLSATARNESSFENTLPNTPSAIQSLTTVSSNSSQNGRSSPKKSFLSKFKLTSRPSTPNVGNTAPDALSSPRNDSPLTSAADEQMKHLSLQEEPKQNPTPAAPGAFPNSNTLPPRYNELGSLPSPNSVSFTEDSRPNVNTPSRRQQIQEEFGSVLQMENRAVSPVYDSRKNGSRSSFTLRKSRSPKRPSSSLSQNASRLPRSLTPGNLEPNYDFGVRVDPASGTAPTDDEPYTDRDSSFVDDTINTKATGNTSNRLSLPAYPTDGGDTSIDNPTSTDGQRILGYVSALYDYDAAIPEEISFRKGDTIAVLKLYEDGWWEGFVVGEDDHNRGQFPSNFVREIEV
UniProtKB AC: Q10199 (positions: 15-311)
Coverage: 44%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: F-BAR domain
Evidence level: Direct evidence
Evidence coverage: The full structure participates in mutual synergistic folding.
Complex Evidence:
F-BAR domains form an intimately packed six-helix bundle and bury a large, hydrophobic dimerization interface. They exist as dimers in solution, with no evidence for monomeric forms (PMID:17512409). Other BAR domains (N-BAR) displayed a two-state equilibrium unfolding (PMID:26368922, PMID:34423187).
Chain A:
N/A
Chain B:
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)
