2UUX

Structure of the tryptase inhibitor TdPI from a tick


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.168 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A Tick Protein with a Modified Kunitz Fold Inhibits Human Tryptase.

Paesen, G.C.Siebold, C.Harlos, K.Peacey, M.F.Nuttall, P.A.Stuart, D.I.

(2007) J.Mol.Biol. 368: 1172

  • DOI: 10.1016/j.jmb.2007.03.011
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • TdPI, a tick salivary gland product related to Kunitz/BPTI proteins is a potent inhibitor of human beta-tryptase. Kinetic assays suggest that three of the four catalytic sites of tryptase are blocked by TdPI, and that the inhibition of one of these i ...

    TdPI, a tick salivary gland product related to Kunitz/BPTI proteins is a potent inhibitor of human beta-tryptase. Kinetic assays suggest that three of the four catalytic sites of tryptase are blocked by TdPI, and that the inhibition of one of these involves a peptide flanking the Kunitz head. In the course of the inhibition, tryptase cleaves TdPI at several positions. Crystal structures of the TdPI head, on its own and in complex with trypsin, reveal features that are not found in classical Kunitz/BPTI proteins and suggest the mode of interaction with tryptase. The loop of TdPI connecting the beta-sheet with the C-terminal alpha-helix is shortened, the disulphide-bridge pattern altered and N and C termini separated to produce a highly pointed molecule capable of penetrating the cramped active sites of tryptase. TdPI accumulates in the cytosolic granules of mast cells, presumably suppressing inflammation in the host animal's skin by tryptase inhibition.


    Organizational Affiliation

    CEH, Mansfield Road, Oxford, OX1 3SR, UK. gcp@ceh.ac.uk




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TRYPTASE INHIBITOR
A
55Rhipicephalus appendiculatusMutation(s): 0 
Find proteins for Q1EG59 (Rhipicephalus appendiculatus)
Go to UniProtKB:  Q1EG59
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.168 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 53.676α = 90.00
b = 28.594β = 90.00
c = 30.110γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
REFMACrefinement
SHELXphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-04-03
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance