Database accession: MF7000587
Name: Rabbit S100A11 (apo form)
PDB ID: 1nsh
Experimental method: NMR
Assembly: Homodimer
Source organism: Oryctolagus cuniculus
Primary publication of the structure:
Dempsey AC, Walsh MP, Shaw GS
Unmasking the annexin I interaction from the structure of Apo-S100A11.
(2003) Structure 11: 887-97
PMID: 12842051
Abstract:
S100A11 is a homodimeric EF-hand calcium binding protein that undergoes a calcium-induced conformational change and interacts with the phospholipid binding protein annexin I to coordinate membrane association. In this work, the solution structure of apo-S100A11 has been determined by NMR spectroscopy to uncover the details of its calcium-induced structural change. Apo-S100A11 forms a tight globular structure having a near antiparallel orientation of helices III and IV in calcium binding site II. Further, helices I and IV, and I and I', form a more closed arrangement than observed in other apo-S100 proteins. This helix arrangement in apo-S100A11 partially buries residues in helices I (P3, E11, A15), III (V55, R58, M59), and IV (A86, C87, S90) and the linker (A45, F46), which are required for interaction with annexin I in the calcium-bound state. In apo-S100A11, this results in a "masked" binding surface that prevents annexin I binding but is uncovered upon calcium binding.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
calcium ion binding calcium ion binding
calcium-dependent protein binding calcium-dependent protein binding
S100 protein binding S100 protein binding
Biological process:
regulation of cell population proliferation regulation of cell population proliferation
Cellular component:
cytoplasm cytoplasm
extracellular space extracellular space
nucleus nucleus
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: Protein S100-A11
Source organism: Oryctolagus cuniculus
Length: 102 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSRPTETERCIESLIAVFQKYAGKDGHSVTLSKTEFLSFMNTELAAFTKNQKDPGVLDRMMKKLDLNSDGQLDFQEFLNLIGGLAVACHESFVKAAPPQKRF
UniProtKB AC: P24480 (positions: 2-102)
Coverage: 99%
Name: Protein S100-A11
Source organism: Oryctolagus cuniculus
Length: 102 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSRPTETERCIESLIAVFQKYAGKDGHSVTLSKTEFLSFMNTELAAFTKNQKDPGVLDRMMKKLDLNSDGQLDFQEFLNLIGGLAVACHESFVKAAPPQKRF
UniProtKB AC: P24480 (positions: 2-102)
Coverage: 99%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: S-100/ICaBP type EF hand dimer
Evidence level: Direct evidence
Evidence coverage: The full structure participates in mutual synergistic folding.
Complex Evidence:
GuHCl-induced denaturation of the S100B protein dimer showed that it follows a two-state unfolding/refolding process (PMID:11888280). Other S100 proteins also showed two-state unfolding, no folded monomers were observed (PMID:18346834, PMID:18706914). The dimer has a globular and compact structure with the four helices in each subunit aligning to form a unicornate-type four-helix bundle (PMID:11790100). The hydrophobic core extends through the dimer interface.
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)
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