Crystal structure of a fammily VIII carboxylesterase in a complex with cephalothin.

Experimental Data Snapshot

  • Resolution: 1.80 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.162 

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Structural basis for the beta-lactamase activity of EstU1, a family VIII carboxylesterase.

Cha, S.S.An, Y.J.Jeong, C.S.Kim, M.K.Jeon, J.H.Lee, C.M.Lee, H.S.Kang, S.G.Lee, J.H.

(2013) Proteins 81: 2045-2051

  • DOI: https://doi.org/10.1002/prot.24334
  • Primary Citation of Related Structures:  
    4IVI, 4IVK

  • PubMed Abstract: 

    EstU1 is a unique family VIII carboxylesterase that displays hydrolytic activity toward the amide bond of clinically used β-lactam antibiotics as well as the ester bond of p-nitrophenyl esters. EstU1 assumes a β-lactamase-like modular architecture and contains the residues Ser100, Lys103, and Tyr218, which correspond to the three catalytic residues (Ser64, Lys67, and Tyr150, respectively) of class C β-lactamases. The structure of the EstU1/cephalothin complex demonstrates that the active site of EstU1 is not ideally tailored to perform an efficient deacylation reaction during the hydrolysis of β-lactam antibiotics. This result explains the weak β-lactamase activity of EstU1 compared with class C β-lactamases. Finally, structural and sequential comparison of EstU1 with other family VIII carboxylesterases elucidates an operative molecular strategy used by family VIII carboxylesterases to extend their substrate spectrum.

  • Organizational Affiliation

    Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan, 426-744, Republic of Korea; Ocean Science and Technology School, Korea Maritime University, Pusan, 606-791, Republic of Korea; Department of Marine Biotechnology, University of Science and Technology, Daejeon, 305-333, Republic of Korea.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Carboxylesterases434uncultured bacteriumMutation(s): 0 
Find proteins for K4HQE7 (uncultured bacterium)
Explore K4HQE7 
Go to UniProtKB:  K4HQE7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupK4HQE7
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.80 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.162 
  • Space Group: I 4 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 149.102α = 90
b = 149.102β = 90
c = 172.571γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-06-19
    Type: Initial release
  • Version 1.1: 2013-10-30
    Changes: Database references
  • Version 1.2: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description