2C1C

Structural basis of the resistance of an insect carboxypeptidase to plant protease inhibitors


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.215 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Basis of the Resistance of an Insect Carboxypeptidase to Plant Protease Inhibitors.

Bayes, A.Comellas-Bigler, M.Rodriguez De La Vega, M.Maskos, K.Bode, W.Aviles, F.X.Jongsma, M.A.Beekwilder, J.Vendrell, J.

(2005) Proc.Natl.Acad.Sci.USA 102: 16602

  • DOI: 10.1073/pnas.0505489102

  • PubMed Abstract: 
  • Corn earworm (Helicoverpa zea), also called tomato fruitworm, is a common pest of many Solanaceous plants. This insect is known to adapt to the ingestion of plant serine protease inhibitors by using digestive proteases that are insensitive to inhibit ...

    Corn earworm (Helicoverpa zea), also called tomato fruitworm, is a common pest of many Solanaceous plants. This insect is known to adapt to the ingestion of plant serine protease inhibitors by using digestive proteases that are insensitive to inhibition. We have now identified a B-type carboxypeptidase of H. zea (CPBHz) insensitive to potato carboxypeptidase inhibitor (PCI) in corn earworm. To elucidate the structural features leading to the adaptation of the insect enzyme, the crystal structure of the recombinant CPBHz protein was determined by x-ray diffraction. CPBHz is a member of the A/B subfamily of metallocarboxypeptidases, which displays the characteristic metallocarboxypeptidase alpha/beta-hydrolase fold, and does not differ essentially from the previously described Helicoverpa armigera CPA, which is very sensitive to PCI. The data provide structural insight into several functional properties of CPBHz. The high selectivity shown by CPBHz for C-terminal lysine residues is due to residue changes in the S1' substrate specificity pocket that render it unable to accommodate the side chain of an arginine. The insensitivity of CPBHz to plant inhibitors is explained by the exceptional positioning of two of the main regions that stabilize other carboxypeptidase-PCI complexes, the beta8-alpha9 loop, and alpha7 together with the alpha7-alpha8 loop. The rearrangement of these two regions leads to a displacement of the active-site entrance that impairs the proper interaction with PCI. This report explains a crystal structure of an insect protease and its adaptation to defensive plant protease inhibitors.


    Organizational Affiliation

    Departament de Bioquímica i Biologia Molecular, Facultat de Ciències, and Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Spain.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CARBOXYPEPTIDASE B
A, B
312Helicoverpa zeaMutation(s): 0 
Gene Names: cpb
EC: 3.4.17.2
Find proteins for Q3T905 (Helicoverpa zea)
Go to UniProtKB:  Q3T905
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Y1
Query on Y1

Download SDF File 
Download CCD File 
A, B
YTTRIUM ION
Y
KAJPZYFHSCFBCI-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.215 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 42.012α = 90.00
b = 58.339β = 89.87
c = 146.564γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
MOSFLMdata reduction
AMoREphasing
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-10-19
    Type: Initial release
  • Version 1.1: 2013-06-26
    Type: Derived calculations, Other, Refinement description, Version format compliance