General Information

Database accession: MF4110001 Original MFIB entry

Name: Transthyretin (rat)

PDB ID: 1gke PDBe

Experimental method: X-ray (2.50 Å)

Assembly: Homotetramer

Source organism: Rattus norvegicus

Primary publication of the structure:

Wojtczak A
Crystal structure of rat transthyretin at 2.5 A resolution: first report on a unique tetrameric structure.

(1997) Acta Biochim. Pol. 44: 505-17

PMID: 9511961 PubMed

Abstract:

The first observation of a unique tetrameric molecular structure of transthyretin from rat (rTTR, prealbumin) is reported. The structure has been determined by X-ray diffraction using molecular replacement and the structure of human transthyretin (hTTR) as a starting model. Crystals of native rat transthyretin are tetragonal, space group P4(3)2(1)2, and have four independent monomers in the asymmetric unit of the crystal lattice. Data were collected to 2.5 A resolution and the structure has been refined to R = 18.9% for 13584 data points between 8-2.5 A resolution. Like hTTR, the rat protein is also a 54000 Da tetramer with four identical polypeptide chains of 127 amino-acid residues. Of the 22 amino-acid residues which are different in the human and rat TTR sequences, none are in the thyroxine binding domain. Analysis of these data reveal that the tertiary structure of rTTR is similar to that of hTTR with only small differences in the flexible loop regions on the surface of the protein. As a result of local changes in flexible loop regions near residues 30-41, 60-65 and 102-104, the structure of rTTR monomers is more compact than that of the corresponding hTTR monomers. The loop between residues 30-41 is bound closer to the monomer core in the former as compared with the latter structure and there is a wider opening of the space formed between these loops at two adjacent monomeric subunits. These conformational changes do not affect the interfaces between the monomeric subunits and are not transmitted to the thyroxine binding site so that its topology remains not altered.


Function and Biology Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown.

Molecular function:

hormone activity hormone activity GeneOntology

hormone binding hormone binding GeneOntology

identical protein binding identical protein binding GeneOntology

protein-containing complex binding protein-containing complex binding GeneOntology

thyroid hormone binding thyroid hormone binding GeneOntology

Biological process:

purine nucleobase metabolic process purine nucleobase metabolic process GeneOntology

thyroid hormone metabolic process thyroid hormone metabolic process GeneOntology

Cellular component:

extracellular space extracellular space GeneOntology

protein-containing complex protein-containing complex GeneOntology

Structure Summary Structural annotations of the participating protein chains.

Entry contents: 4 distinct polypeptide molecules

Chains: A, B, C, D

Notes: All chains according to the most probable oligomerization state stored in PDBe were considered.

Number of unique protein segments: 1


Chain A

Name: Transthyretin

Source organism: Rattus norvegicus

Length: 147 residues

Sequence:Sequence according to the corresponding UniProt protein segmentMASLRLFLLCLAGLIFASEAGPGGAGESKCPLMVKVLDAVRGSPAVDVAVKVFKKTADGSWEPFASGKTAESGELHGLTTDEKFTEGVYRVELDTKSYWKALGISPFHEYAEVVFTANDSGHRHYTIAALLSPYSYSTTAVVSNPQN

UniProtKB AC: P02767 (positions: 28-147) UniProt

Coverage: 81%

Chain B

Name: Transthyretin

Source organism: Rattus norvegicus

Length: 147 residues

Sequence:Sequence according to the corresponding UniProt protein segmentMASLRLFLLCLAGLIFASEAGPGGAGESKCPLMVKVLDAVRGSPAVDVAVKVFKKTADGSWEPFASGKTAESGELHGLTTDEKFTEGVYRVELDTKSYWKALGISPFHEYAEVVFTANDSGHRHYTIAALLSPYSYSTTAVVSNPQN

UniProtKB AC: P02767 (positions: 28-147) UniProt

Coverage: 81%

Chain C

Name: Transthyretin

Source organism: Rattus norvegicus

Length: 147 residues

Sequence:Sequence according to the corresponding UniProt protein segmentMASLRLFLLCLAGLIFASEAGPGGAGESKCPLMVKVLDAVRGSPAVDVAVKVFKKTADGSWEPFASGKTAESGELHGLTTDEKFTEGVYRVELDTKSYWKALGISPFHEYAEVVFTANDSGHRHYTIAALLSPYSYSTTAVVSNPQN

UniProtKB AC: P02767 (positions: 28-147) UniProt

Coverage: 81%

Chain D

Name: Transthyretin

Source organism: Rattus norvegicus

Length: 147 residues

Sequence:Sequence according to the corresponding UniProt protein segmentMASLRLFLLCLAGLIFASEAGPGGAGESKCPLMVKVLDAVRGSPAVDVAVKVFKKTADGSWEPFASGKTAESGELHGLTTDEKFTEGVYRVELDTKSYWKALGISPFHEYAEVVFTANDSGHRHYTIAALLSPYSYSTTAVVSNPQN

UniProtKB AC: P02767 (positions: 28-147) UniProt

Coverage: 81%

Evidence Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding.

Representative domain in related structures: HIUase/Transthyretin family

Evidence level: Direct evidence

Evidence coverage: The full structure participates in mutual synergistic folding.

Complex Evidence:

Transthyretin was shown in calorimetrics experiments to follow two-state folding/binding kinetics with the emergence of structure being linked to oligomerization (PMID:11152276).

Chain A:

N/A

Chain B:

N/A

Chain C:

N/A

Chain D:

N/A

Surface and contacts features:

Related Structure(s) 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).

There are 7 related structures in the MFIB database:
The molecule viewer shows our modified stucture.

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