PDBsum entry 1ecy

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protein ligands links
Protease inhibitor PDB id
Protein chain
142 a.a. *
GLC ×4
Waters ×80
* Residue conservation analysis
PDB id:
Name: Protease inhibitor
Title: Protease inhibitor ecotin
Structure: Ecotin. Chain: a. Engineered: yes. Other_details: escherichia coli protease inhibitor
Source: Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 562.
Biol. unit: Dimer (from PQS)
2.19Å     R-factor:   0.213     R-free:   0.319
Authors: D.H.Shin,S.W.Suh
Key ref:
D.H.Shin et al. (1996). Crystal structure analyses of uncomplexed ecotin in two crystal forms: implications for its function and stability. Protein Sci, 5, 2236-2247. PubMed id: 8931142 DOI: 10.1002/pro.5560051110
06-Aug-96     Release date:   12-Feb-97    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
P23827  (ECOT_ECOLI) -  Ecotin
162 a.a.
142 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     periplasmic space   1 term 
  Biological process     negative regulation of peptidase activity in other organism   3 terms 
  Biochemical function     protein binding     3 terms  


DOI no: 10.1002/pro.5560051110 Protein Sci 5:2236-2247 (1996)
PubMed id: 8931142  
Crystal structure analyses of uncomplexed ecotin in two crystal forms: implications for its function and stability.
D.H.Shin, H.K.Song, I.S.Seong, C.S.Lee, C.H.Chung, S.W.Suh.
Ecotin, a homodimeric protein composed of 142 residue subunits, is a novel serine protease inhibitor present in Escherichia coli. Its thermostability and acid stability, as well as broad specificity toward proteases, make it an interesting protein for structural characterization. Its structure in the uncomplexed state, determined for two different crystalline environments, allows a structural comparison of the free inhibitor with that in complex with trypsin. Although there is no gross structural rearrangement of ecotin when binding trypsin, the loops involved in binding trypsin show relatively large shifts in atomic positions. The inherent flexibility of the loops and the highly nonglobular shape are the two features essential for its inhibitory function. An insight into the understanding of the structural basis of thermostability and acid stability of ecotin is also provided by the present structure.
  Selected figure(s)  
Figure 6.
Fig. 6. Stereo diagrams comparing the regions of thc inhihitor that interact with trypsin and show rel- a~~vcly I;~rge RMSL mong complcxed (light lines). uncomplcxed ~ypc 1 (gr~y lines). and uncomplcxed type I1 (hlack lines)ecolin truclurcs. A: Residues 82-89. H: Residues 50-55. C: Resides 6-70, ): Residue\ 99-105.
Figure 8.
ig. 8. Molecular surface of uncomplexed ecotin (in orthorhombic, type crystal) colored according to electrostatic potential. osi- tively charged regions are and negatively harged regions red.Top: when the viewon the left side is rotatedby 180 around the vertical axis, the viwo theright is obtained. Bottom: the left view is fromthe side andtheright viewis from the top. Figures were generated using GRASP Nicholls, 1992).
  The above figures are reprinted from an Open Access publication published by the Protein Society: Protein Sci (1996, 5, 2236-2247) copyright 1996.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
19292875 M.F.Montenegro, M.T.Moral-Naranjo, E.Muñoz-Delgado, F.J.Campoy, and C.J.Vidal (2009).
Hydrolysis of acetylthiocoline, o-nitroacetanilide and o-nitrotrifluoroacetanilide by fetal bovine serum acetylcholinesterase.
  FEBS J, 276, 2074-2083.  
19016791 S.C.Eschenlauer, M.S.Faria, L.S.Morrison, N.Bland, F.L.Ribeiro-Gomes, G.A.DosReis, G.H.Coombs, A.P.Lima, and J.C.Mottram (2009).
Influence of parasite encoded inhibitors of serine peptidases in early infection of macrophages with Leishmania major.
  Cell Microbiol, 11, 106-120.  
15502324 I.T.Campos, B.G.Guimarães, F.J.Medrano, A.S.Tanaka, and J.A.Barbosa (2004).
Crystallization, data collection and phasing of infestin 4, a factor XIIa inhibitor.
  Acta Crystallogr D Biol Crystallogr, 60, 2051-2053.  
12484463 N.Felitsyn, E.N.Kitova, and J.S.Klassen (2002).
Thermal dissociation of the protein homodimer ecotin in the gas phase.
  J Am Soc Mass Spectrom, 13, 1432-1442.  
11468352 M.D.Person, K.C.Brown, S.Mahrus, C.S.Craik, and A.L.Burlingame (2001).
Novel inter-protein cross-link identified in the GGH-ecotin D137Y dimer.
  Protein Sci, 10, 1549-1562.  
10216315 C.S.Lee, I.S.Seong, H.K.Song, C.H.Chung, and S.W.Suh (1999).
Crystallization and preliminary X-ray crystallographic analysis of the protease inhibitor ecotin in complex with chymotrypsin.
  Acta Crystallogr D Biol Crystallogr, 55, 1091-1092.  
9521759 K.C.Brown, Z.Yu, A.L.Burlingame, and C.S.Craik (1998).
Determining protein-protein interactions by oxidative cross-linking of a glycine-glycine-histidine fusion protein.
  Biochemistry, 37, 4397-4406.  
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.