Covalent Reaction intermediate Revealed in Crystal Structure of the Geobacillus stearothermophilus Carboxylesterase Est30

Experimental Data Snapshot

  • Resolution: 1.63 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.168 

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Covalent reaction intermediate revealed in crystal structure of the Geobacillus stearothermophilus carboxylesterase Est30.

Liu, P.Wang, Y.F.Ewis, H.E.Abdelal, A.T.Lu, C.D.Harrison, R.W.Weber, I.T.

(2004) J Mol Biol 342: 551-561

  • DOI: https://doi.org/10.1016/j.jmb.2004.06.069
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Est30 is a thermophilic carboxylesterase cloned from Geobacillus stearothermophilus that showed optimal hydrolysis of esters with short acyl chains at 70 degrees C. Est30 is a member of a new family of carboxylesterases with representatives in other Gram-positive bacteria. The crystal structure has been determined at 1.63A resolution using multiple anomalous dispersion data. The two-domain crystal structure showed a large domain with a modified alpha/beta hydrolase core including a seven, rather than an eight-stranded beta sheet, and a smaller cap domain comprising three alpha helices. The catalytic triad consists of residues Ser94, Asp193, and His223. A 100Da tetrahedral ligand was observed to be covalently bound to the side-chain of Ser94. The propyl acetate ligand represents the first tetrahedral intermediate in the reaction mechanism. Therefore, this Est30 crystal structure will help understand the mode of action of all enzymes in the serine hydrolase superfamily.

  • Organizational Affiliation

    Department of Biology, Molecular Basis of Disease Program, Georgia State University, Atlanta, GA 30303, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Carboxylesterase precursor247Geobacillus stearothermophilusMutation(s): 0 
Find proteins for Q06174 (Geobacillus stearothermophilus)
Explore Q06174 
Go to UniProtKB:  Q06174
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ06174
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.63 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.168 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.654α = 90
b = 58.205β = 90
c = 179.045γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
RESOLVEmodel building
ARP/wARPmodel building
MAR345data collection
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-09-28
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2014-04-30
    Changes: Data collection
  • Version 1.4: 2017-10-11
    Changes: Refinement description