Database accession: MF4120005
Name: 5-hydroxyisourate hydrolase (Escherichia coli)
PDB ID: 2g2n
Experimental method: X-ray (1.65 Å)
Assembly: Homotetramer
Source organism: Escherichia coli
Primary publication of the structure:
Lundberg E, Bäckström S, Sauer UH, Sauer-Eriksson AE
The transthyretin-related protein: structural investigation of a novel protein family.
(2006) J. Struct. Biol. 155: 445-57
PMID: 16723258
Abstract:
The transthyretin-related protein (TRP) family comprises proteins predicted to be structurally related to the homotetrameric transport protein transthyretin (TTR). The function of TRPs is not yet fully established, but recent data suggest that they are involved in purine catabolism. We have determined the three-dimensional structure of the Escherichia coli TRP in two crystal forms; one at 1.65 A resolution in the presence of zinc, and the other at 2.1 A resolution in the presence of zinc and bromide. The structures revealed five zinc-ion-binding sites per monomer. Of these, the zinc ions bound at sites I and II are coordinated in tetrahedral geometries to the side chains of residues His9, His96, His98, Ser114, and three water molecules at the putative ligand-binding site. Of these four residues, His9, His98, and Ser114 are conserved. His9 and His98 bind the central zinc (site I) together with two water molecules. The side chain of His98 also binds to the zinc ion at site II. Bromide ions bind at site I only, replacing one of the water molecules coordinated to the zinc ion. The C-terminal four amino acid sequence motif Y-[RK]-G-[ST] constitutes the signature sequence of the TRP family. Two Tyr111 residues form direct hydrogen bonds to each other over the tetramer interface at the area, which in TTR constitutes the rear part of its thyroxine-binding channel. The putative substrate/ligand-binding channel of TRP is consequently shallower and broader than its counterpart in TTR.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
hydroxyisourate hydrolase activity hydroxyisourate hydrolase activity
identical protein binding identical protein binding
Biological process:
protein homotetramerization protein homotetramerization
purine nucleobase metabolic process purine nucleobase metabolic process
Cellular component:
periplasmic space periplasmic space
protein-containing complex protein-containing complex
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
Name: 5-hydroxyisourate hydrolase
Source organism: Escherichia coli
Length: 137 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMLKRYLVLSVATAAFSLPSLVNAAQQNILSVHILNQQTGKPAADVTVTLEKKADNGWLQLNTAKTDKDGRIKALWPEQTATTGDYRVVFKTGDYFKKQNLESFFPEIPVEFHINKVNEHYHVPLLLSQYGYSTYRGS
UniProtKB AC: P76341 (positions: 27-137)
Coverage: 81%
Name: 5-hydroxyisourate hydrolase
Source organism: Escherichia coli
Length: 137 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMLKRYLVLSVATAAFSLPSLVNAAQQNILSVHILNQQTGKPAADVTVTLEKKADNGWLQLNTAKTDKDGRIKALWPEQTATTGDYRVVFKTGDYFKKQNLESFFPEIPVEFHINKVNEHYHVPLLLSQYGYSTYRGS
UniProtKB AC: P76341 (positions: 27-137)
Coverage: 81%
Name: 5-hydroxyisourate hydrolase
Source organism: Escherichia coli
Length: 137 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMLKRYLVLSVATAAFSLPSLVNAAQQNILSVHILNQQTGKPAADVTVTLEKKADNGWLQLNTAKTDKDGRIKALWPEQTATTGDYRVVFKTGDYFKKQNLESFFPEIPVEFHINKVNEHYHVPLLLSQYGYSTYRGS
UniProtKB AC: P76341 (positions: 26-137)
Coverage: 81%
Name: 5-hydroxyisourate hydrolase
Source organism: Escherichia coli
Length: 137 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMLKRYLVLSVATAAFSLPSLVNAAQQNILSVHILNQQTGKPAADVTVTLEKKADNGWLQLNTAKTDKDGRIKALWPEQTATTGDYRVVFKTGDYFKKQNLESFFPEIPVEFHINKVNEHYHVPLLLSQYGYSTYRGS
UniProtKB AC: P76341 (positions: 26-137)
Coverage: 81%
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:
The protein belongs to the 5-hydroxyisourate hydrolase (HIUase)/transthyretin protein family. Accordingly, the complex adopts a transthyterin-like fold (based on Pfam entry PF00576.18 and the publication PMID:16723258). 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:
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)
