Database accession: MF4120004
Name: 5-hydroxyisourate hydrolase (Klebsiella pneumoniae)
PDB ID: 3qva
Experimental method: X-ray (1.76 Å)
Assembly: Homotetramer
Source organism: Klebsiella pneumoniae subsp pneumoniae
Primary publication of the structure:
French JB, Ealick SE
Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae.
(2011) Acta Crystallogr. D Biol. Crystallogr. 67: 671-7
PMID: 21795808
Abstract:
The stereospecific oxidative degradation of uric acid to (S)-allantoin has recently been demonstrated to proceed via two unstable intermediates and requires three separate enzymatic reactions. The second step of this reaction, the conversion of 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, is catalyzed by HIU hydrolase (HIUH). The high-resolution crystal structure of HIUH from the opportunistic pathogen Klebsiella pneumoniae (KpHIUH) has been determined. KpHIUH is a homotetrameric protein that, based on sequence and structural similarity, belongs to the transthyretin-related protein family. In addition, the steady-state kinetic parameters for this enzyme and four active-site mutants have been measured. These data provide valuable insight into the functional roles of the active-site residues. Based upon the structural and kinetic data, a mechanism is proposed for the KpHIUH-catalyzed reaction.
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
Biological process:
purine nucleobase metabolic process purine nucleobase metabolic process
Cellular component: not assigned
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: Klebsiella pneumoniae subsp pneumoniae
Length: 108 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSTLSTHILDISTGTPAEGVTVSLSREGETLANLVTNAQGRIATFSAAPLPAGRYCLTAETGAWFARAGRESVFTRAQIDFVIGEAAEDHFHLPFLIAPGGWSTYRGS
UniProtKB AC: A6T926 (positions: 1-108)
Coverage: 100%
Name: 5-hydroxyisourate hydrolase
Source organism: Klebsiella pneumoniae subsp pneumoniae
Length: 108 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSTLSTHILDISTGTPAEGVTVSLSREGETLANLVTNAQGRIATFSAAPLPAGRYCLTAETGAWFARAGRESVFTRAQIDFVIGEAAEDHFHLPFLIAPGGWSTYRGS
UniProtKB AC: A6T926 (positions: 1-107)
Coverage: 99%
Name: 5-hydroxyisourate hydrolase
Source organism: Klebsiella pneumoniae subsp pneumoniae
Length: 108 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSTLSTHILDISTGTPAEGVTVSLSREGETLANLVTNAQGRIATFSAAPLPAGRYCLTAETGAWFARAGRESVFTRAQIDFVIGEAAEDHFHLPFLIAPGGWSTYRGS
UniProtKB AC: A6T926 (positions: 1-108)
Coverage: 100%
Name: 5-hydroxyisourate hydrolase
Source organism: Klebsiella pneumoniae subsp pneumoniae
Length: 108 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMSTLSTHILDISTGTPAEGVTVSLSREGETLANLVTNAQGRIATFSAAPLPAGRYCLTAETGAWFARAGRESVFTRAQIDFVIGEAAEDHFHLPFLIAPGGWSTYRGS
UniProtKB AC: A6T926 (positions: 2-108)
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: 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:21795808). 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)
