Ubiquitous Structural Signaling in Bacterial Phytochromes Academic Article uri icon


  • The phytochrome family of light-switchable proteins has long been studied by biochemical, spectroscopic and crystallographic means, while a direct probe for global conformational signal propagation has been lacking. Using solution X-ray scattering, we find that the photosensory cores of several bacterial phytochromes undergo similar large-scale structural changes upon red-light excitation. The data establish that phytochromes with ordinary and inverted photocycles share a structural signaling mechanism and that a particular conserved histidine, previously proposed to be involved in signal propagation, in fact tunes photoresponse.


  • Bjorling, A
  • Berntsson, O
  • Takala, H
  • Gallagher, KD
  • Patel, H
  • Gustavsson, E
  • St Peter, R
  • Phu, D
  • Nugent, A
  • Zhang, F
  • Berntsen, P
  • Appio, R
  • Rajkovic, I
  • Lehtivuori, H
  • Panman, MR
  • Hoernke, M
  • Niebling, S
  • Harimoorthy, R
  • Lamparter, T
  • Stojkovic, EA
  • Ihalainen, JA
  • Westenhoff, S

publication date

  • 2015