Bacteriophytochrome response regulator RtBRR

Experimental Data Snapshot

  • Resolution: 1.90 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.179 

wwPDB Validation   3D Report Full Report

This is version 1.4 of the entry. See complete history


Arm-in-Arm Response Regulator Dimers Promote Intermolecular Signal Transduction.

Baker, A.W.Satyshur, K.A.Moreno Morales, N.Forest, K.T.

(2016) J Bacteriol 198: 1218-1229

  • DOI: https://doi.org/10.1128/JB.00872-15
  • Primary Citation of Related Structures:  
    5BRJ, 5IC5

  • PubMed Abstract: 

    Bacteriophytochrome photoreceptors (BphPs) and their cognate response regulators make up two-component signal transduction systems which direct bacteria to mount phenotypic responses to changes in environmental light quality. Most of these systems utilize single-domain response regulators to transduce signals through unknown pathways and mechanisms. Here we describe the photocycle and autophosphorylation kinetics of RtBphP1, a red light-regulated histidine kinase from the desert bacterium Ramlibacter tataouinensis RtBphP1 undergoes red to far-red photoconversion with rapid thermal reversion to the dark state. RtBphP1 is autophosphorylated in the dark; this activity is inhibited under red light. The RtBphP1 cognate response regulator, the R. tataouinensis bacteriophytochrome response regulator (RtBRR), and a homolog, AtBRR from Agrobacterium tumefaciens, crystallize unexpectedly as arm-in-arm dimers, reliant on a conserved hydrophobic motif, hFWAhL (where h is a hydrophobic M, V, L, or I residue). RtBRR and AtBRR dimerize distinctly from four structurally characterized phytochrome response regulators found in photosynthetic organisms and from all other receiver domain homodimers in the Protein Data Bank. A unique cacodylate-zinc-histidine tag metal organic framework yielded single-wavelength anomalous diffraction phases and may be of general interest. Examination of the effect of the BRR stoichiometry on signal transduction showed that phosphorylated RtBRR is accumulated more efficiently than the engineered monomeric RtBRR (RtBRRmon) in phosphotransfer reactions. Thus, we conclude that arm-in-arm dimers are a relevant signaling intermediate in this class of two-component regulatory systems. BphP histidine kinases and their cognate response regulators comprise widespread red light-sensing two-component systems. Much work on BphPs has focused on structural understanding of light sensing and on enhancing the natural infrared fluorescence of these proteins, rather than on signal transduction or the resultant phenotypes. To begin to address this knowledge gap, we solved the crystal structures of two single-domain response regulators encoded by a region immediately downstream of that encoding BphPs. We observed a previously unknown arm-in-arm dimer linkage. Monomerization via deletion of the C-terminal dimerization motif had an inhibitory effect on net response regulator phosphorylation, underlining the importance of these unusual dimers for signal transduction.

  • Organizational Affiliation

    Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Candidate response regulator, CheY166Ramlibacter tataouinensis TTB310Mutation(s): 0 
Gene Names: Rta_25480
Find proteins for F5Y2U8 (Ramlibacter tataouinensis (strain ATCC BAA-407 / DSM 14655 / LMG 21543 / TTB310))
Explore F5Y2U8 
Go to UniProtKB:  F5Y2U8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupF5Y2U8
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.714α = 90
b = 47.714β = 90
c = 193.488γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Science Foundation (NSF, United States)United StatesDGE-1256259
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States5T32GM008349-23
National Science Foundation (NSF, United States)United StatesMCB 1518160

Revision History  (Full details and data files)

  • Version 1.0: 2016-03-02
    Type: Initial release
  • Version 1.1: 2017-09-20
    Changes: Author supporting evidence, Derived calculations
  • Version 1.2: 2019-11-27
    Changes: Author supporting evidence
  • Version 1.3: 2020-10-21
    Changes: Data collection, Derived calculations
  • Version 1.4: 2024-03-06
    Changes: Data collection, Database references