PDBsum entry 2c7b

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protein Protein-protein interface(s) links
Hydrolase PDB id
Protein chains
295 a.a. *
Waters ×138
* Residue conservation analysis
PDB id:
Name: Hydrolase
Title: The crystal structure of este1, a new thermophilic and thermostable carboxylesterase cloned from a metagenomic library
Structure: Carboxylesterase. Chain: a, b. Fragment: alpha-beta hydrolase fold, residues 1-311. Synonym: este1. Engineered: yes
Source: Uncultured archaeon. Organism_taxid: 115547. Expressed in: escherichia coli. Expression_system_taxid: 469008. Other_details: metagenomes from thermal environmental samples
Biol. unit: Tetramer (from PDB file)
2.3Å     R-factor:   0.233     R-free:   0.261
Authors: J.-S.Byun,J.-K.Rhee,D.-U.Kim,J.-W.Oh,H.-S.Cho
Key ref: J.S.Byun et al. (2007). Crystal structure of hyperthermophilic esterase EstE1 and the relationship between its dimerization and thermostability properties. BMC Struct Biol, 7, 47. PubMed id: 17625021
21-Nov-05     Release date:   01-Dec-05    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
Q5G935  (Q5G935_9ARCH) -  Carboxylesterase
311 a.a.
295 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.  - Carboxylesterase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: A carboxylic ester + H2O = an alcohol + a carboxylate
carboxylic ester
+ H(2)O
= alcohol
+ carboxylate
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     metabolic process   1 term 
  Biochemical function     carboxylic ester hydrolase activity     2 terms  


BMC Struct Biol 7:47 (2007)
PubMed id: 17625021  
Crystal structure of hyperthermophilic esterase EstE1 and the relationship between its dimerization and thermostability properties.
J.S.Byun, J.K.Rhee, N.D.Kim, J.Yoon, D.U.Kim, E.Koh, J.W.Oh, H.S.Cho.
BACKGROUND: EstE1 is a hyperthermophilic esterase belonging to the hormone-sensitive lipase family and was originally isolated by functional screening of a metagenomic library constructed from a thermal environmental sample. Dimers and oligomers may have been evolutionally selected in thermophiles because intersubunit interactions can confer thermostability on the proteins. The molecular mechanisms of thermostabilization of this extremely thermostable esterase are not well understood due to the lack of structural information. RESULTS: Here we report for the first time the 2.1-A resolution crystal structure of EstE1. The three-dimensional structure of EstE1 exhibits a classic alpha/beta hydrolase fold with a central parallel-stranded beta sheet surrounded by alpha helices on both sides. The residues Ser154, Asp251, and His281 form the catalytic triad motif commonly found in other alpha/beta hydrolases. EstE1 exists as a dimer that is formed by hydrophobic interactions and salt bridges. Circular dichroism spectroscopy and heat inactivation kinetic analysis of EstE1 mutants, which were generated by structure-based site-directed mutagenesis of amino acid residues participating in EstE1 dimerization, revealed that hydrophobic interactions through Val274 and Phe276 on the beta8 strand of each monomer play a major role in the dimerization of EstE1. In contrast, the intermolecular salt bridges contribute less significantly to the dimerization and thermostability of EstE1. CONCLUSION: Our results suggest that intermolecular hydrophobic interactions are essential for the hyperthermostability of EstE1. The molecular mechanism that allows EstE1 to endure high temperature will provide guideline for rational design of a thermostable esterase/lipase using the lipolytic enzymes showing structural similarity to EstE1.

Literature references that cite this PDB file's key reference

  PubMed id Reference
21179190 E.Venner, A.M.Lisewski, S.Erdin, R.M.Ward, S.R.Amin, and O.Lichtarge (2010).
Accurate protein structure annotation through competitive diffusion of enzymatic functions over a network of local evolutionary similarities.
  PLoS One, 5, e14286.  
20967243 M.A.Zhukovsky, S.Basmaciogullari, B.Pacheco, L.Wang, N.Madani, H.Haim, and J.Sodroski (2010).
Thermal stability of the human immunodeficiency virus type 1 (HIV-1) receptors, CD4 and CXCR4, reconstituted in proteoliposomes.
  PLoS One, 5, e13249.  
19544040 M.Levisson, J.van der Oost, and S.W.Kengen (2009).
Carboxylic ester hydrolases from hyperthermophiles.
  Extremophiles, 13, 567-581.  
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