Database accession: MF7000601
Name: Human S100A1 (apo form)
PDB ID: 2l0p
Experimental method: NMR
Assembly: Homodimer
Source organism: Homo sapiens
Primary publication of the structure:
Nowakowski M, Jaremko Ł, Jaremko M, Zhukov I, Belczyk A, Bierzyński A, Ejchart A
Solution NMR structure and dynamics of human apo-S100A1 protein.
(2011) J. Struct. Biol. 174: 391-9
PMID: 21296671
Abstract:
S100A1 belongs to the EF-hand superfamily of calcium binding proteins. It is a representative of the S100 protein family based on amino acid sequence, three-dimensional structure, and biological function as a calcium signal transmitter. It is a homodimer of noncovalently bound subunits. S100A1, like most of other members of the S100 protein family, is a multifunctional, regulatory protein involved in a large variety of biological processes and closely associated with several human diseases. The three-dimensional structure of human apo-(i.e. calcium free)-S100A1 protein was determined by NMR spectroscopy (PDB 2L0P) and its backbone dynamics established by ¹⁵N magnetic relaxation. Comparison of these results with the structure and backbone dynamics previously determined for bovine apo-S100A1 protein modified by disulfide formation with β-mercaptoethanol at Cys 85 revealed that the secondary structure of both these proteins was almost identical, whereas the global structure of the latter was much more mobile than that of human apo-S100 protein. Differences between the structures of human and rat apo-S100A1 are also discussed.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
ATPase binding ATPase binding
calcium ion binding calcium ion binding
calcium-dependent protein binding calcium-dependent protein binding
identical protein binding identical protein binding
protein homodimerization activity protein homodimerization activity
S100 protein binding S100 protein binding
Biological process:
intracellular signal transduction intracellular signal transduction
positive regulation of nitric-oxide synthase activity positive regulation of nitric-oxide synthase activity
positive regulation of sprouting angiogenesis positive regulation of sprouting angiogenesis
regulation of heart contraction regulation of heart contraction
substantia nigra development substantia nigra development
Cellular component:
cytoplasm cytoplasm
cytosol cytosol
extracellular region extracellular region
Golgi apparatus Golgi apparatus
mitochondrion mitochondrion
nucleoplasm nucleoplasm
nucleus nucleus
protein-containing complex protein-containing complex
sarcoplasmic reticulum sarcoplasmic reticulum
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-A1
Source organism: Homo sapiens
Length: 94 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMGSELETAMETLINVFHAHSGKEGDKYKLSKKELKELLQTELSGFLDAQKDVDAVDKVMKELDENGDGEVDFQEYVVLVAALTVACNNFFWENS
UniProtKB AC: P23297 (positions: 2-94)
Coverage: 98%
Name: Protein S100-A1
Source organism: Homo sapiens
Length: 94 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMGSELETAMETLINVFHAHSGKEGDKYKLSKKELKELLQTELSGFLDAQKDVDAVDKVMKELDENGDGEVDFQEYVVLVAALTVACNNFFWENS
UniProtKB AC: P23297 (positions: 2-94)
Coverage: 98%
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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