Database accession: MF7000955
Name: N-terminal dimerization domain of Sgt2
PDB ID: 4asv
Experimental method: NMR
Assembly: Homodimer
Source organism: Saccharomyces cerevisiae
Primary publication of the structure:
Simon AC, Simpson PJ, Goldstone RM, Krysztofinska EM, Murray JW, High S, Isaacson RL
Structure of the Sgt2/Get5 complex provides insights into GET-mediated targeting of tail-anchored membrane proteins.
(2013) Proc. Natl. Acad. Sci. U.S.A. 110: 1327-32
PMID: 23297211
Abstract:
Small, glutamine-rich, tetratricopeptide repeat protein 2 (Sgt2) is the first known port of call for many newly synthesized tail-anchored (TA) proteins released from the ribosome and destined for the GET (Guided Entry of TA proteins) pathway. This leads them to the residential membrane of the endoplasmic reticulum via an alternative to the cotranslational, signal recognition particle-dependent mechanism that their topology denies them. In yeast, the first stage of the GET pathway involves Sgt2 passing TA proteins on to the Get4/Get5 complex through a direct interaction between the N-terminal (NT) domain of Sgt2 and the ubiquitin-like (UBL) domain of Get5. Here we characterize this interaction at a molecular level by solving both a solution structure of Sgt2_NT, which adopts a unique helical fold, and a crystal structure of the Get5_UBL. Furthermore, using reciprocal chemical shift perturbation data and experimental restraints, we solve a structure of the Sgt2_NT/Get5_UBL complex, validate it via site-directed mutagenesis, and empirically determine its stoichiometry using relaxation experiments and isothermal titration calorimetry. Taken together, these data provide detailed structural information about the interaction between two key players in the coordinated delivery of TA protein substrates into the GET pathway.
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
molecular adaptor activity molecular adaptor activity
Biological process:
post-translational protein targeting to endoplasmic reticulum membrane post-translational protein targeting to endoplasmic reticulum membrane
response to heat response to heat
Cellular component:
cytoplasm cytoplasm
cytosol cytosol
membrane membrane
TRC complex TRC complex
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: Small glutamine-rich tetratricopeptide repeat-containing protein 2
Source organism: Saccharomyces cerevisiae
Length: 346 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSASKEEIAALIVNYFSSIVEKKEISEDGADSLNVAMDCISEAFGFEREAVSGILGKSEFKGQHLADILNSASRVPESNKKDDAENVEINIPEDDAETKAKAEDLKMQGNKAMANKDYELAINKYTEAIKVLPTNAIYYANRAAAHSSLKEYDQAVKDAESAISIDPSYFRGYSRLGFAKYAQGKPEEALEAYKKVLDIEGDNATEAMKRDYESAKKKVEQSLNLEKTVPEQSRDADVDASQGASAGGLPDLGSLLGGGLGGLMNNPQLMQAAQKMMSNPGAMQNIQKMMQDPSIRQMAEGFASGGGTPNLSDLMNNPALRNMAGNLFGGAGAQSTDETPDNENKQ
UniProtKB AC: Q12118 (positions: 1-78)
Coverage: 22%
Name: Small glutamine-rich tetratricopeptide repeat-containing protein 2
Source organism: Saccharomyces cerevisiae
Length: 346 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSASKEEIAALIVNYFSSIVEKKEISEDGADSLNVAMDCISEAFGFEREAVSGILGKSEFKGQHLADILNSASRVPESNKKDDAENVEINIPEDDAETKAKAEDLKMQGNKAMANKDYELAINKYTEAIKVLPTNAIYYANRAAAHSSLKEYDQAVKDAESAISIDPSYFRGYSRLGFAKYAQGKPEEALEAYKKVLDIEGDNATEAMKRDYESAKKKVEQSLNLEKTVPEQSRDADVDASQGASAGGLPDLGSLLGGGLGGLMNNPQLMQAAQKMMSNPGAMQNIQKMMQDPSIRQMAEGFASGGGTPNLSDLMNNPALRNMAGNLFGGAGAQSTDETPDNENKQ
UniProtKB AC: Q12118 (positions: 1-78)
Coverage: 22%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: Homodimerisation domain of SGTA
Evidence level: Indirect evidence
Evidence coverage: The full structure participates in mutual synergistic folding.
Complex Evidence:
The dimer interface is highly hydrophobic, the hydrophobic core is contributed by both monomers, mutations introduced to block dimer formation yielded no soluble protein (PMID:23297211).
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)
