2QPQ

Structure of Bug27 from Bordetella pertussis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.92 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure-based mechanism of ligand binding for periplasmic solute-binding protein of the Bug family.

Herrou, J.Bompard, C.Antoine, R.Leroy, A.Rucktooa, P.Hot, D.Huvent, I.Locht, C.Villeret, V.Jacob-Dubuisson, F.

(2007) J.Mol.Biol. 373: 954-964

  • DOI: 10.1016/j.jmb.2007.08.006

  • PubMed Abstract: 
  • Bug proteins form a large family of periplasmic solute-binding proteins well represented in beta-proteobacteria. They adopt a characteristic Venus flytrap fold with two globular domains bisected by a ligand-binding cleft. The structures of two ligand ...

    Bug proteins form a large family of periplasmic solute-binding proteins well represented in beta-proteobacteria. They adopt a characteristic Venus flytrap fold with two globular domains bisected by a ligand-binding cleft. The structures of two liganded Bug proteins have revealed that the family is specific for carboxylated solutes, with a characteristic mode of binding involving two highly conserved beta strand-beta turn-alpha helix motifs originating from each domain. These two motifs form hydrogen bonds with a carboxylate group of the ligand, both directly and via conserved water molecules, and have thus been termed the carboxylate pincers. In both crystallized Bug proteins, the ligands were found enclosed between the two domains and inaccessible to solvent, suggesting an inter-domain hinge-bending motion upon ligand binding. We report here the first structures of an open, unliganded Bug protein and of the same protein with a citrate ion bound in the open cavity. One of the ligand carboxylate groups is bound to one half of the carboxylate pincers by the beta strand-beta turn-alpha helix motif from domain 1, and the citrate ion forms several additional interactions with domain 1. The ligand is accessible to solvent and has very few contacts with domain 2. In this open, liganded structure, the second part of the carboxylate pincers originating from domain 2 is not stabilized by ligand binding, and a loop replaces the beta turn. In the unliganded structure, both motifs of the carboxylate pincers are highly mobile, and neither of the two beta turns is formed. Thus, ligand recognition is performed by domain 1, with the carboxylate group serving as an initial anchoring point. Stabilization of the closed conformation requires proper interactions to be established with domain 2, and thus domain 2 discriminates between productively and non-productively bound ligands.


    Organizational Affiliation

    INSERM U629, 1 Rue du Pr Calmette, 59019 Lille cedex, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
protein Bug27
A, B, C
301Bordetella pertussis (strain Tohama I / ATCC BAA-589 / NCTC 13251)Mutation(s): 0 
Find proteins for Q7W019 (Bordetella pertussis (strain Tohama I / ATCC BAA-589 / NCTC 13251))
Go to UniProtKB:  Q7W019
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CIT
Query on CIT

Download SDF File 
Download CCD File 
A, C
CITRIC ACID
C6 H8 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
CITKd: 430 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.92 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.191 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 72.390α = 90.00
b = 82.310β = 95.35
c = 87.470γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
REFMACrefinement
MAR345dtbdata collection
XSCALEdata scaling
SHARPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-08-21
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance