5K7F

Crystal structure of apo AibR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.208 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The AibR-isovaleryl coenzyme A regulator and its DNA binding site - a model for the regulation of alternative de novo isovaleryl coenzyme A biosynthesis in Myxococcus xanthus.

Bock, T.Volz, C.Hering, V.Scrima, A.Muller, R.Blankenfeldt, W.

(2017) Nucleic Acids Res 45: 2166-2178

  • DOI: https://doi.org/10.1093/nar/gkw1238
  • Primary Citation of Related Structures:  
    5K7F, 5K7H

  • PubMed Abstract: 

    Isovaleryl coenzyme A (IV-CoA) is an important building block of iso-fatty acids. In myxobacteria, IV-CoA is essential for the formation of signaling molecules involved in fruiting body formation. Leucine degradation is the common source of IV-CoA, but a second, de novo biosynthetic route to IV-CoA termed AIB (alternative IV-CoA biosynthesis) was recently discovered in M. xanthus. The AIB-operon contains the TetR-like transcriptional regulator AibR, which we characterize in this study. We demonstrate that IV-CoA binds AibR with micromolar affinity and show by gelshift experiments that AibR interacts with the promoter region of the AIB-operon once IV-CoA is present. We identify an 18-bp near-perfect palindromic repeat as containing the AibR operator and provide evidence that AibR also controls an additional genomic locus coding for a putative acetyl-CoA acetyltransferase. To elucidate atomic details, we determined crystal structures of AibR in the apo, the IV-CoA- and the IV-CoA-DNA-bound state to 1.7 Å, 2.35 Å and 2.92 Å, respectively. IV-CoA induces partial unfolding of an α-helix, which allows sequence-specific interactions between AibR and its operator. This study provides insights into AibR-mediated regulation and shows that AibR functions in an unusual TetR-like manner by blocking transcription not in the ligand-free but in the effector-bound state.


  • Organizational Affiliation

    Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124 Braunschweig, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Transcriptional regulator, TetR family
A, B
231Myxococcus xanthus DK 1622Mutation(s): 0 
Gene Names: MXAN_4263
UniProt
Find proteins for Q1D4I5 (Myxococcus xanthus (strain DK1622))
Explore Q1D4I5 
Go to UniProtKB:  Q1D4I5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ1D4I5
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT

Download Ideal Coordinates CCD File 
C [auth B]ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.208 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.664α = 90
b = 95.225β = 105.55
c = 62.051γ = 90
Software Package:
Software NamePurpose
Aimlessdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
SHELXCDphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-12-21
    Type: Initial release
  • Version 1.1: 2017-05-03
    Changes: Database references
  • Version 1.2: 2024-05-08
    Changes: Data collection, Database references