1GL1

structure of the complex between bovine alpha-chymotrypsin and PMP-C, an inhibitor from the insect Locusta migratoria


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.189 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Complexation of Two Proteic Insect Inhibitors to the Active Site of Chymotrypsin Suggests Decoupled Roles for Binding and Selectivity

Roussel, A.Mathieu, M.Dobbs, A.Luu, B.Cambillau, C.Kellenberger, C.

(2001) J Biol Chem 276: 38893

  • DOI: 10.1074/jbc.M105707200
  • Primary Citation of Related Structures:  
    1GL0, 1GL1

  • PubMed Abstract: 
  • The crystal structures of two homologous inhibitors (PMP-C and PMP-D2v) from the insect Locusta migratoria have been determined in complex with bovine alpha-chymotrypsin at 2.1- and 3.0-A resolution, respectively. PMP-C is a potent bovine alpha-chymotrypsin inhibitor whereas native PMP-D2 is a weak inhibitor of bovine trypsin ...

    The crystal structures of two homologous inhibitors (PMP-C and PMP-D2v) from the insect Locusta migratoria have been determined in complex with bovine alpha-chymotrypsin at 2.1- and 3.0-A resolution, respectively. PMP-C is a potent bovine alpha-chymotrypsin inhibitor whereas native PMP-D2 is a weak inhibitor of bovine trypsin. One unique mutation at the P1 position converts PMP-D2 into a potent bovine alpha-chymotrypsin inhibitor. The two peptides have a similar overall conformation, which consists of a triple-stranded antiparallel beta-sheet connected by three disulfide bridges, thus defining a novel family of serine protease inhibitors. They have in common the protease interaction site, which is composed of the classical protease binding loop (position P5 to P'4, corresponding to residues 26-34) and of an internal segment (residues 15-18), held together by two disulfide bridges. Structural divergences between the two inhibitors result in an additional interaction site between PMP-D2v (position P10 to P6, residues 21-25) and the residues 172-175 of alpha-chymotrypsin. This unusual interaction may be responsible for species selectivity. A careful comparison of data on bound and free inhibitors (from this study and previous NMR studies, respectively) suggests that complexation to the protease stabilizes the flexible binding loop (from P5 to P'4).


    Organizational Affiliation

    Architecture et Fonction de Macromolecules Biologiques, UMR-6098, CNRS et Universités d'Aix-Marseille I et II, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. roussel@afmb.cnrs-mrs.fr



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ALPHA-CHYMOTRYPSINA, B, C245Bos taurusMutation(s): 0 
EC: 3.4.21.1
UniProt
Find proteins for P00766 (Bos taurus)
Explore P00766 
Go to UniProtKB:  P00766
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
PROTEASE INHIBITOR LCMI IID [auth I], E [auth J], F [auth K]36Locusta migratoriaMutation(s): 0 
UniProt
Find proteins for P80060 (Locusta migratoria)
Explore P80060 
Go to UniProtKB:  P80060
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.189 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 92.958α = 90
b = 92.958β = 90
c = 165.841γ = 120
Software Package:
Software NamePurpose
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-11-28
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance