3HHS

Crystal Structure of Manduca sexta prophenoloxidase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.97 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.154 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of Manduca sexta prophenoloxidase provides insights into the mechanism of type 3 copper enzymes.

Li, Y.Wang, Y.Jiang, H.Deng, J.

(2009) Proc.Natl.Acad.Sci.USA 106: 17002-17006

  • DOI: 10.1073/pnas.0906095106

  • PubMed Abstract: 
  • Arthropod phenoloxidase (PO) generates quinones and other toxic compounds to sequester and kill pathogens during innate immune responses. It is also involved in wound healing and other physiological processes. Insect PO is activated from its inactive ...

    Arthropod phenoloxidase (PO) generates quinones and other toxic compounds to sequester and kill pathogens during innate immune responses. It is also involved in wound healing and other physiological processes. Insect PO is activated from its inactive precursor, prophenoloxidase (PPO), by specific proteolysis via a serine protease cascade. Here, we report the crystal structure of PPO from a lepidopteran insect at a resolution of 1.97 A, which is the initial structure for a PPO from the type 3 copper protein family. Manduca sexta PPO is a heterodimer consisting of 2 homologous polypeptide chains, PPO1 and PPO2. The active site of each subunit contains a canonical type 3 di-nuclear copper center, with each copper ion coordinated with 3 structurally conserved histidines. The acidic residue Glu-395 located at the active site of PPO2 may serve as a general base for deprotonation of monophenolic substrates, which is key to the ortho-hydroxylase activity of PO. The structure provides unique insights into the mechanism by which type 3 copper proteins differ in their enzymatic activities, albeit sharing a common active center. A drastic change in electrostatic surface induced on cleavage at Arg-51 allows us to propose a model for localized PPO activation in insects.


    Organizational Affiliation

    Department of Biochemistry, Oklahoma State University, Stillwater, OK 74078, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Phenoloxidase subunit 2
A
694Manduca sextaMutation(s): 0 
Gene Names: ppo
EC: 1.14.18.1
Find proteins for Q25519 (Manduca sexta)
Go to UniProtKB:  Q25519
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Phenoloxidase subunit 1
B
684Manduca sextaMutation(s): 0 
EC: 1.14.18.1
Find proteins for O44249 (Manduca sexta)
Go to UniProtKB:  O44249
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CU
Query on CU

Download SDF File 
Download CCD File 
A, B
COPPER (II) ION
Cu
JPVYNHNXODAKFH-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.97 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.154 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 148.832α = 90.00
b = 153.664β = 90.00
c = 75.763γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-09-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Refinement description, Version format compliance
  • Version 1.2: 2017-11-01
    Type: Advisory, Refinement description