Secreted type 1 cystatin from Fasciola hepatica

Experimental Data Snapshot

  • Resolution: 1.60 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.219 

wwPDB Validation   3D Report Full Report

This is version 1.1 of the entry. See complete history


An evolutionary molecular adaptation of an unusual stefin from the liver fluke Fasciola hepatica redefines the cystatin superfamily.

Busa, M.Matouskova, Z.Bartosova-Sojkova, P.Pachl, P.Rezacova, P.Eichenberger, R.M.Deplazes, P.Horn, M.Stefanic, S.Mares, M.

(2023) J Biol Chem 299: 102970-102970

  • DOI: https://doi.org/10.1016/j.jbc.2023.102970
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Fasciolosis is a worldwide parasitic disease of ruminants and an emerging human disease caused by the liver fluke Fasciola hepatica. The cystatin superfamily of cysteine protease inhibitors is composed of distinct families of intracellular stefins and secreted true cystatins. FhCyLS-2 from F. hepatica is an unusual member of the superfamily, where our sequence and 3D structure analyses in this study revealed that it combines characteristics of both families. The protein architecture demonstrates its relationship to stefins, but FhCyLS-2 also contains the secretion signal peptide and disulfide bridges typical of true cystatins. The secretion status was confirmed by detecting the presence of FhCyLS-2 in excretory/secretory products, supported by immunolocalization. Our high-resolution crystal structure of FhCyLS-2 showed a distinct disulfide bridging pattern and functional reactive center. We determined that FhCyLS-2 is a broad specificity inhibitor of cysteine cathepsins from both the host and F. hepatica, suggesting a dual role in the regulation of exogenous and endogenous proteolysis. Based on phylogenetic analysis that identified several FhCyLS-2 homologues in liver/intestinal foodborne flukes, we propose a new group within the cystatin superfamily called cystatin-like stefins.

  • Organizational Affiliation

    Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia; Department of Biochemistry, Faculty of Science, Charles University, Prague, Czechia.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cystatin93Fasciola hepaticaMutation(s): 0 
Gene Names: Cyt
Find proteins for A0A2H1BUS1 (Fasciola hepatica)
Explore A0A2H1BUS1 
Go to UniProtKB:  A0A2H1BUS1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A2H1BUS1
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.60 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.219 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 64.878α = 90
b = 67.177β = 90
c = 44.493γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
European Regional Development FundCzech RepublicCZ.02.1.01/0.0/0.0/16_019/0000729
Czech Academy of SciencesCzech Republic61388963
Ministry of Education, Youth and Sports of the Czech RepublicCzech RepublicLO1304

Revision History  (Full details and data files)

  • Version 1.0: 2020-08-26
    Type: Initial release
  • Version 1.1: 2023-03-29
    Changes: Database references