2K2N

Solution structure of a cyanobacterial phytochrome GAF domain in the red light-absorbing ground state


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Solution structure of a cyanobacterial phytochrome GAF domain in the red-light-absorbing ground state.

Cornilescu, G.Ulijasz, A.T.Cornilescu, C.C.Markley, J.L.Vierstra, R.D.

(2008) J.Mol.Biol. 383: 403-413

  • DOI: 10.1016/j.jmb.2008.08.034
  • Primary Citation of Related Structures:  
  • Also Cited By: 2KOI

  • PubMed Abstract: 
  • The unique photochromic absorption behavior of phytochromes (Phys) depends on numerous reversible interactions between the bilin chromophore and the associated polypeptide. To help define these dynamic interactions, we determined by NMR spectroscopy ...

    The unique photochromic absorption behavior of phytochromes (Phys) depends on numerous reversible interactions between the bilin chromophore and the associated polypeptide. To help define these dynamic interactions, we determined by NMR spectroscopy the first solution structure of the chromophore-binding cGMP phosphodiesterase/adenylcyclase/FhlA (GAF) domain from a cyanobacterial Phy assembled with phycocyanobilin (PCB). The three-dimensional NMR structure of Synechococcus OS-B' cyanobacterial Phy 1 in the red-light-absorbing state of Phy (Pr) revealed that PCB is bound to Cys138 of the GAF domain via the A-ring ethylidene side chain and is buried within the GAF domain in a ZZZsyn,syn,anti configuration. The D ring of the chromophore sits within a hydrophobic pocket and is tilted by approximately 80 degrees relative to the B/C rings by contacts with Lys52 and His169. The solution structure revealed remarkable flexibility for PCB and several adjacent amino acids, indicating that the Pr chromophore has more freedom in the binding pocket than anticipated. The propionic acid side chains of rings B and C and Arg101 and Arg133 nearby are especially mobile and can assume several distinct and energetically favorable conformations. Mutagenic studies on these arginines, which are conserved within the Phy superfamily, revealed that they have opposing roles, with Arg101 and Arg133 helping stabilize and destabilize the far-red-light-absorbing state of Phy (Pfr), respectively. Given the fact that the Synechococcus OS-B' GAF domain can, by itself, complete the Pr --> Pfr photocycle, it should now be possible to determine the solution structure of the Pfr chromophore and surrounding pocket using this Pr structure as a framework.


    Organizational Affiliation

    National Magnetic Resonance Facility at Madison, University of Wisconsin, Madison, WI 53706, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Sensor protein
A
172Synechococcus sp. (strain JA-2-3B'a(2-13))
Find proteins for Q2JIZ5 (Synechococcus sp. (strain JA-2-3B'a(2-13)))
Go to UniProtKB:  Q2JIZ5
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CYC
Query on CYC

Download SDF File 
Download CCD File 
A
PHYCOCYANOBILIN
C33 H40 N4 O6
VXTXPYZGDQPMHK-GMXXPEQVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2K2N Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-09-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance