3QJ3

Structure of digestive procathepsin L2 proteinase from Tenebrio molitor larval midgut


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.186 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

The 3D structure and function of digestive cathepsin L-like proteinases of Tenebrio molitor larval midgut.

Beton, D.Guzzo, C.R.Ribeiro, A.F.Farah, C.S.Terra, W.R.

(2012) Insect Biochem Mol Biol 42: 655-664

  • DOI: https://doi.org/10.1016/j.ibmb.2012.04.010
  • Primary Citation of Related Structures:  
    3QJ3, 3QT4

  • PubMed Abstract: 

    Cathepsin L-like proteinases (CAL) are major digestive proteinases in the beetle Tenebrio molitor. Procathepsin Ls 2 (pCAL2) and 3 (pCAL3) were expressed as recombinant proteins in Escherichia coli, purified and activated under acidic conditions. Immunoblot analyses of different T. molitor larval tissues demonstrated that a polyclonal antibody to pCAL3 recognized pCAL3 and cathepsin L 3 (CAL3) only in the anterior two-thirds of midgut tissue and midgut luminal contents of T. molitor larvae. Furthermore, immunocytolocalization data indicated that pCAL3 occurs in secretory vesicles and microvilli in anterior midgut. Therefore CAL3, like cathepsin L 2 (CAL2), is a digestive enzyme secreted by T. molitor anterior midgut. CAL3 hydrolyses Z-FR-MCA and Z-RR-MCA (typical cathepsin substrates), whereas CAL2 hydrolyses only Z-FR-MCA. Active site mutants (pCAL2C25S and pCAL3C26S) were constructed by replacing the catalytic cysteine with serine to prevent autocatalytic processing. Recombinant pCAL2 and pCAL3 mutants (pCAL2C25S and pCAL3C26S) were prepared, crystallized and their 3D structures determined at 1.85 and 2.1 Å, respectively. While the overall structure of these enzymes is similar to other members of the papain superfamily, structural differences in the S2 subsite explain their substrate specificities. The data also supported models for CAL trafficking to lysosomes and to secretory vesicles to be discharged into midgut contents.


  • Organizational Affiliation

    Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, C. P. 26077, 05513-970 São Paulo, Brazil.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cathepsin L-like protein
A, B
331Tenebrio molitorMutation(s): 1 
Gene Names: pCAL2
EC: 3.4.22.15
UniProt
Find proteins for Q69G21 (Tenebrio molitor)
Explore Q69G21 
Go to UniProtKB:  Q69G21
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ69G21
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.186 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.669α = 91.28
b = 52.37β = 91.55
c = 59.716γ = 109.59
Software Package:
Software NamePurpose
MAR345data collection
PHASERphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-02-01
    Type: Initial release
  • Version 1.1: 2012-06-20
    Changes: Database references
  • Version 1.2: 2012-08-22
    Changes: Database references
  • Version 1.3: 2017-11-08
    Changes: Refinement description
  • Version 1.4: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description