Gene Symbol: eco
Description: ecotin, a serine protease inhibitor
Alias: ECK2201, JW2197, eti
Species: Escherichia coli str. K-12 substr. MG1655
Products:     eco

Top Publications

  1. Jin L, Pandey P, Babine R, Gorga J, Seidl K, Gelfand E, et al. Crystal structures of the FXIa catalytic domain in complex with ecotin mutants reveal substrate-like interactions. J Biol Chem. 2005;280:4704-12 pubmed
    ..These structures provide us with an understanding of substrate binding interactions of FXIa, the structural information essential for the structure-based design of FXIa-selective inhibitors. ..
  2. McGrath M, Erpel T, Browner M, Fletterick R. Expression of the protease inhibitor ecotin and its co-crystallization with trypsin. J Mol Biol. 1991;222:139-42 pubmed
    ..7 A, and indicate that they belong to the monoclinic space group, P21. The cell constants are a = 52.0 A, b = 93.3 A, c = 160.7 A, and beta = 96 degrees. Four molecules each of trypsin and ecotin are found in the asymmetric unit. ..
  3. McGrath M, Hines W, Sakanari J, Fletterick R, Craik C. The sequence and reactive site of ecotin. A general inhibitor of pancreatic serine proteases from Escherichia coli. J Biol Chem. 1991;266:6620-5 pubmed
    ..The reactive site of ecotin was determined to be Met84 for its complexes with chymotrypsin, trypsin, and elastase. The scissile Met84-Met85 bond lies within a disulfide-bonded protein segment similar to other classes of inhibitors. ..
  4. Sathler P, Craik C, Takeuchi T, Zingali R, Castro H. Engineering ecotin for identifying proteins with a trypsin fold. Appl Biochem Biotechnol. 2010;160:2355-65 pubmed publisher
    ..Thus, they may assist in the understanding of the role of these serine proteases and homologous proteins in different biological processes. ..
  5. McGrath M, Erpel T, Bystroff C, Fletterick R. Macromolecular chelation as an improved mechanism of protease inhibition: structure of the ecotin-trypsin complex. EMBO J. 1994;13:1502-7 pubmed
    ..This first case of protein dimerization being used to augment binding energy and allow chelation of a target protein provides a new model for protein-protein interactions and for protease inhibition. ..
  6. Laboissière M, Young M, Pinho R, Todd S, Fletterick R, Kuntz I, et al. Computer-assisted mutagenesis of ecotin to engineer its secondary binding site for urokinase inhibition. J Biol Chem. 2002;277:26623-31 pubmed
    ..This technology can be applied to select for enhanced binding interactions at protein-protein interfaces and accelerate the process of protease inhibitor development. ..
  7. Pal G, Szilagyi L, Graf L. Stable monomeric form of an originally dimeric serine proteinase inhibitor, ecotin, was constructed via site directed mutagenesis. FEBS Lett. 1996;385:165-70 pubmed
    ..Our data suggest that this heterotetramer exists even in extremely diluted solutions, and the interaction, which is responsible for the dimerization of ecotin, contributes to the stability of the heterotetrameric complex. ..
  8. Takeuchi T, Shuman M, Craik C. Reverse biochemistry: use of macromolecular protease inhibitors to dissect complex biological processes and identify a membrane-type serine protease in epithelial cancer and normal tissue. Proc Natl Acad Sci U S A. 1999;96:11054-61 pubmed
    ..Ecotin and variant ecotins are subnanomolar inhibitors of the MT-SP1 activated protease domain, suggesting a possible role for MT-SP1 in prostate differentiation and the growth of prostatic carcinomas. ..
  9. Gillmor S, Takeuchi T, Yang S, Craik C, Fletterick R. Compromise and accommodation in ecotin, a dimeric macromolecular inhibitor of serine proteases. J Mol Biol. 2000;299:993-1003 pubmed
    ..A comparison with two recently described ecotin-like genes from other bacteria suggests that these structural and functional features are conserved in otherwise distant bacterial lineages. ..

More Information


  1. Seong I, Lee H, Seol J, Park S, Lee C, Suh S, et al. The P1 reactive site methionine residue of ecotin is not crucial for its specificity on target proteases. A potent inhibitor of pancreatic serine proteases from Escherichia coli. J Biol Chem. 1994;269:21915-8 pubmed
    ..These results strongly suggest that the P1 site of ecotin is not crucial for its specificity on target proteases and that the disulfide bridge in ecotin appears to play an important role in maintenance of its structural stability. ..
  2. Chu F, Baker P, Burlingame A, Chalkley R. Finding chimeras: a bioinformatics strategy for identification of cross-linked peptides. Mol Cell Proteomics. 2010;9:25-31 pubmed publisher
  3. Seymour J, Lindquist R, Dennis M, Moffat B, Yansura D, Reilly D, et al. Ecotin is a potent anticoagulant and reversible tight-binding inhibitor of factor Xa. Biochemistry. 1994;33:3949-58 pubmed
    ..The P1 Arg and Lys mutants also significantly inhibited thrombin, factor XIa, activated protein C, plasmin, factor XIIa, kallikrein, and bovine trypsin and chymotrypsin but did not inhibit tissue factor.factor VIIa, t-PA, or HLE. ..
  4. Eggers C, Wang S, Fletterick R, Craik C. The role of ecotin dimerization in protease inhibition. J Mol Biol. 2001;308:975-91 pubmed
    ..Such a mechanism of adaptability allows femtomolar affinities for two proteases with very different specificities. ..
  5. McGrath M, Gillmor S, Fletterick R. Ecotin: lessons on survival in a protease-filled world. Protein Sci. 1995;4:141-8 pubmed
    ..The binding sites show a fluidity of protein contacts derived from ecotin's innate flexibility in fitting itself to proteases while strongly interfering with their function. ..
  6. Wang C, Yang Q, Craik C. Isolation of a high affinity inhibitor of urokinase-type plasminogen activator by phage display of ecotin. J Biol Chem. 1995;270:12250-6 pubmed
    ..Each of the selected ecotin variants exhibited increased affinity for uPA when compared to wild-type ecotin with ecotin M84R/M85R showing a 2800-fold increase in binding affinity. ..
  7. Lee C, Seong I, Song H, Chung C, Suh S. Crystallization and preliminary X-ray crystallographic analysis of the protease inhibitor ecotin in complex with chymotrypsin. Acta Crystallogr D Biol Crystallogr. 1999;55:1091-2 pubmed
    ..58 A3 Da-1 and a solvent fraction of 48.9%. The crystals diffract beyond 2.0 A with Cu Kalpha X-rays and are very stable in the X-ray beam. Native X-ray data have been collected from a crystal to approximately 2.0 A Bragg spacing. ..
  8. Yang S, Craik C. Engineering bidentate macromolecular inhibitors for trypsin and urokinase-type plasminogen activator. J Mol Biol. 1998;279:1001-11 pubmed
    ..The fact that the 60 s loop of ecotin plays different roles in binding to trypsin and uPA suggests this site can be used to introduce specificity and potency for other members of the serine proteases with a chymotrypsin fold. ..
  9. Erpel T, Hwang P, Craik C, Fletterick R, McGrath M. Physical map location of the new Escherichia coli gene eco, encoding the serine protease inhibitor ecotin. J Bacteriol. 1992;174:1704 pubmed
  10. Corey D, Shiau A, Yang Q, Janowski B, Craik C. Trypsin display on the surface of bacteriophage. Gene. 1993;128:129-34 pubmed
    ..An endogenous Escherichia coli protease inhibitor, ecotin, copurifies with the Tsn phage. Immobilized ecotin can be used to selectively bind bacteriophage which express Tsn::pIII fusion proteins. ..
  11. Shin D, Song H, Seong I, Lee C, Chung C, Suh S. Crystal structure analyses of uncomplexed ecotin in two crystal forms: implications for its function and stability. Protein Sci. 1996;5:2236-47 pubmed
    ..An insight into the understanding of the structural basis of thermostability and acid stability of ecotin is also provided by the present structure. ..
  12. Pal G, Sprengel G, Patthy A, Graf L. Alteration of the specificity of ecotin, an E. coli serine proteinase inhibitor, by site directed mutagenesis. FEBS Lett. 1994;342:57-60 pubmed
    ..According to our results the character of residue 84 of ecotin significantly but not dramatically modifies the specificity of the inhibitor. ..
  13. Ulmer J, Lindquist R, Dennis M, Lazarus R. Ecotin is a potent inhibitor of the contact system proteases factor XIIa and plasma kallikrein. FEBS Lett. 1995;365:159-63 pubmed
  14. Lee H, Seo J, Kim O, Lee C, Suh S, Hong Y, et al. Molecular cloning of the ecotin gene in Escherichia coli. FEBS Lett. 1991;287:53-6 pubmed
    ..Ecotin does not contain any consensus reactive site sequences of known serine protease inhibitor families, suggesting that Ecotin is a novel inhibitor. ..
  15. Eggers C, Murray I, Delmar V, Day A, Craik C. The periplasmic serine protease inhibitor ecotin protects bacteria against neutrophil elastase. Biochem J. 2004;379:107-18 pubmed
    ..This suggests that an important part of the antimicrobial mechanism of neutrophil elastase may be a periplasmic bacteriostatic effect of protease that has translocated across the damaged outer membrane. ..
  16. Dobbins S, Lesk V, Sternberg M. Insights into protein flexibility: The relationship between normal modes and conformational change upon protein-protein docking. Proc Natl Acad Sci U S A. 2008;105:10390-5 pubmed publisher
    ..We discuss the implications of the results for the mechanics of protein recognition. ..
  17. Wang S, Hur E, Sousa C, Brinen L, Slivka E, Fletterick R. The extended interactions and Gla domain of blood coagulation factor Xa. Biochemistry. 2003;42:7959-66 pubmed
    ..The first 11 residues of the domain assume a novel conformation and likely represent an intermediate folding state of the domain. ..
  18. Lengyel Z, Pal G, Sahin Toth M. Affinity purification of recombinant trypsinogen using immobilized ecotin. Protein Expr Purif. 1998;12:291-4 pubmed
    ..In this study we demonstrate that immobilized ecotin, a unique protease inhibitor from Escherichia coli, provides a superior affinity matrix for the purification of trypsinogen and possibly other serine protease zymogens as well. ..
  19. Yang S, Wang C, Gillmor S, Fletterick R, Craik C. Ecotin: a serine protease inhibitor with two distinct and interacting binding sites. J Mol Biol. 1998;279:945-57 pubmed
    ..Ecotin binds to proteases with a chymotrypsin fold through a combination of primary and secondary site surface loops and is amenable to redesign of its potency and specificity for this class of enzymes. ..
  20. Brown K, Yu Z, Burlingame A, Craik C. Determining protein-protein interactions by oxidative cross-linking of a glycine-glycine-histidine fusion protein. Biochemistry. 1998;37:4397-406 pubmed
    ..This cross-linking methodology allows for the protein cross-linking reagent to be encoded for at the DNA level, thus circumventing the need for posttranslational modification. ..
  21. Perona J, Tsu C, Craik C, Fletterick R. Crystal structure of an ecotin-collagenase complex suggests a model for recognition and cleavage of the collagen triple helix. Biochemistry. 1997;36:5381-92 pubmed
    ..The capacity for such rearrangement appears to be a key determinant of its ability to inhibit a wide range of serine proteases. ..
  22. Chung C, Ives H, Almeda S, Goldberg A. Purification from Escherichia coli of a periplasmic protein that is a potent inhibitor of pancreatic proteases. J Biol Chem. 1983;258:11032-8 pubmed
    ..The physiological function of this E. coli trypsin inhibitor is unknown. We suggest that E. coli trypsin inhibitor be named "Ecotin." ..
  23. Mosolov V. [New studies on natural inhibitors of proteolytic enzymes]. Bioorg Khim. 1998;24:332-40 pubmed
    ..Special emphasis is placed on enzyme inhibition with propeptides and the mechanism of this process. ..
  24. Castro H, Monteiro R, Assafim M, Loureiro N, Craik C, Zingali R. Ecotin modulates thrombin activity through exosite-2 interactions. Int J Biochem Cell Biol. 2006;38:1893-900 pubmed
    ..At this point, ecotin might be useful as a new tool for studying thrombin allosteric modulation. ..
  25. Shin D, Hwang K, Kim K, Lee H, Lee C, Chung C, et al. Crystallization and preliminary X-ray crystallographic analysis of the protease inhibitor ecotin. J Mol Biol. 1993;229:1157-8 pubmed
    ..55 A3/Da and a solvent content of 51.8% by volume. The crystals diffract to at least 2.2 A using a conventional X-ray source, and X-ray data have been collected to 2.7 A Bragg spacing from a native crystal. ..
  26. Palmer S, St John A. Characterization of a membrane-associated serine protease in Escherichia coli. J Bacteriol. 1987;169:1474-9 pubmed
    ..All three membrane-associated serine proteases were insensitive to inhibition by Ecotin, and endogenous, periplasmic inhibitor of trypsin. ..
  27. McCrudden M, Ryan L, Turkington P, Timson D. The contribution of key hydrophobic residues in ecotin to enzyme-inhibitor complex stability. J Enzyme Inhib Med Chem. 2009;24:1207-10 pubmed publisher
    ..Each of these mutant ecotin proteins tested in kinetic assays with these enzymes exerted less inhibitory potency compared to wild-type ecotin. However, these effects were relatively small and not additive. ..