5DDO

Structural and Dynamic Basis for Low Affinity-High Selectivity Binding of L-glutamine by the Gln-riboswitch


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.1 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.227 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural and Dynamic Basis for Low-Affinity, High-Selectivity Binding of L-Glutamine by the Glutamine Riboswitch.

Ren, A.Xue, Y.Peselis, A.Serganov, A.Al-Hashimi, H.M.Patel, D.J.

(2015) Cell Rep 13: 1800-1813

  • DOI: 10.1016/j.celrep.2015.10.062
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Naturally occurring L-glutamine riboswitches occur in cyanobacteria and marine metagenomes, where they reside upstream of genes involved in nitrogen metabolism. By combining X-ray, NMR, and MD, we characterized an L-glutamine-dependent conformational ...

    Naturally occurring L-glutamine riboswitches occur in cyanobacteria and marine metagenomes, where they reside upstream of genes involved in nitrogen metabolism. By combining X-ray, NMR, and MD, we characterized an L-glutamine-dependent conformational transition in the Synechococcus elongatus glutamine riboswitch from tuning fork to L-shaped alignment of stem segments. This transition generates an open ligand-binding pocket with L-glutamine selectivity enforced by Mg(2+)-mediated intermolecular interactions. The transition also stabilizes the P1 helix through a long-range "linchpin" Watson-Crick G-C pair-capping interaction, while melting a short helix below P1 potentially capable of modulating downstream readout. NMR data establish that the ligand-free glutamine riboswitch in Mg(2+) solution exists in a slow equilibrium between flexible tuning fork and a minor conformation, similar, but not identical, to the L-shaped bound conformation. We propose that an open ligand-binding pocket combined with a high conformational penalty for forming the ligand-bound state provide mechanisms for reducing binding affinity while retaining high selectivity.


    Organizational Affiliation

    Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
U1 small nuclear ribonucleoprotein A
G, C
97Homo sapiensMutation(s): 2 
Gene Names: SNRPA
Find proteins for P09012 (Homo sapiens)
Go to Gene View: SNRPA
Go to UniProtKB:  P09012
Entity ID: 1
MoleculeChainsLengthOrganism
L-glutamine riboswitch (58-MER)A,B61Synechococcus elongatus
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.1 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.227 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 80.840α = 90.00
b = 99.652β = 99.05
c = 88.461γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2015-08-25 
  • Released Date: 2015-12-23 
  • Deposition Author(s): Ren, A., Patel, D.

Funding OrganizationLocationGrant Number
National Institutes of Health/National Cancer InstituteUnited States1 U19 CA179564

Revision History 

  • Version 1.0: 2015-12-23
    Type: Initial release
  • Version 1.1: 2017-04-05
    Type: Derived calculations
  • Version 1.2: 2017-09-20
    Type: Author supporting evidence