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PDBsum entry 2ogt

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protein ligands metals links
Hydrolase PDB id
2ogt
Jmol
Contents
Protein chain
463 a.a. *
Ligands
GOL ×2
Metals
IOD
Waters ×147
* Residue conservation analysis
PDB id:
2ogt
Name: Hydrolase
Title: Crystal structure of the geobacillus stearothermophilus carboxylesterase est55 at ph 6.8
Structure: Thermostable carboxylesterase est50. Chain: a. Engineered: yes
Source: Geobacillus stearothermophilus. Organism_taxid: 1422. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
1.58Å     R-factor:   0.176     R-free:   0.241
Authors: P.Liu,H.E.Ewis,P.C.Tai,C.D.Lu,I.T.Weber
Key ref:
P.Liu et al. (2007). Crystal structure of the Geobacillus stearothermophilus carboxylesterase Est55 and its activation of prodrug CPT-11. J Mol Biol, 367, 212-223. PubMed id: 17239398 DOI: 10.1016/j.jmb.2006.12.067
Date:
08-Jan-07     Release date:   13-Feb-07    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
Q8GCC7  (Q8GCC7_GEOSE) -  Thermostable carboxylesterase Est50
Seq:
Struc:
498 a.a.
463 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     metabolic process   1 term 
  Biochemical function     hydrolase activity     1 term  

 

 
DOI no: 10.1016/j.jmb.2006.12.067 J Mol Biol 367:212-223 (2007)
PubMed id: 17239398  
 
 
Crystal structure of the Geobacillus stearothermophilus carboxylesterase Est55 and its activation of prodrug CPT-11.
P.Liu, H.E.Ewis, P.C.Tai, C.D.Lu, I.T.Weber.
 
  ABSTRACT  
 
Several mammalian carboxylesterases were shown to activate the prodrug irinotecan (CPT-11) to produce 7-ethyl-10-hydroxycamptothecin (SN-38), a topoisomerase inhibitor used in cancer therapy. However, the potential use of bacterial carboxylesterases, which have the advantage of high stability, has not been explored. We present the crystal structure of the carboxyesterase Est55 from Geobacillus stearothermophilus and evaluation of its enzyme activity on CPT-11. Crystal structures were determined at pH 6.2 and pH 6.8 and resolution of 2.0 A and 1.58 A, respectively. Est55 folds into three domains, a catalytic domain, an alpha/beta domain and a regulatory domain. The structure is in an inactive form; the side-chain of His409, one of the catalytic triad residues, is directed away from the other catalytic residues Ser194 and Glu310. Moreover, the adjacent Cys408 is triply oxidized and lies in the oxyanion hole, which would block the binding of substrate, suggesting a regulatory role. However, Cys408 is not essential for enzyme activity. Mutation of Cys408 showed that hydrophobic side-chains were favorable, while polar serine was unfavorable for enzyme activity. Est55 was shown to hydrolyze CPT-11 into the active form SN-38. The mutant C408V provided a more stable enzyme for activation of CPT-11. Therefore, engineered thermostable Est55 is a candidate for use with irinotecan in enzyme-prodrug cancer therapy.
 
  Selected figure(s)  
 
Figure 2.
Figure 2. Superposition of Est55 and human carboxylesterase hCE1 structures. Est55 is in green and hCE1 is in red. The active sites are within the ellipse. The black arrow indicates the regulatory domain, which shows significant differences between the two structures. Figure 2. Superposition of Est55 and human carboxylesterase hCE1 structures. Est55 is in green and hCE1 is in red. The active sites are within the ellipse. The black arrow indicates the regulatory domain, which shows significant differences between the two structures.
Figure 4.
Figure 4. (a) The active site region of Est55. Inter-atomic interactions are shown as broken lines with distances in Å. The catalytic residues Ser194, Glu310 and His409 are labeled in red. (b) Comparison of active sites of Est55 (green) and hCE1 (red). The catalytic triad residues of hCE1 are Ser221, Glu354, and His468. Cys408 in Est55 is equivalent to Asp467 in hCE1. Figure 4. (a) The active site region of Est55. Inter-atomic interactions are shown as broken lines with distances in Å. The catalytic residues Ser194, Glu310 and His409 are labeled in red. (b) Comparison of active sites of Est55 (green) and hCE1 (red). The catalytic triad residues of hCE1 are Ser221, Glu354, and His468. Cys408 in Est55 is equivalent to Asp467 in hCE1.
 
  The above figures are reprinted from an Open Access publication published by Elsevier: J Mol Biol (2007, 367, 212-223) copyright 2007.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21538236 W.Tao, M.H.Lee, J.Wu, N.H.Kim, and S.W.Lee (2011).
Isolation and characterization of a family VII esterase derived from alluvial soil metagenomic library.
  J Microbiol, 49, 178-185.  
20467738 S.Billig, T.Oeser, C.Birkemeyer, and W.Zimmermann (2010).
Hydrolysis of cyclic poly(ethylene terephthalate) trimers by a carboxylesterase from Thermobifida fusca KW3.
  Appl Microbiol Biotechnol, 87, 1753-1764.  
18031336 N.Kuisiene, J.Raugalas, M.Stuknyte, and D.Chitavichius (2007).
Identification of the genus Geobacillus using genus-specific primers, based on the 16S-23S rRNA gene internal transcribed spacer.
  FEMS Microbiol Lett, 277, 165-172.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.