Ubiquitous Structural Signaling in Bacterial Phytochromes.

Research output: Contribution to journalArticle


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.


  • Alexander Björling
  • Oskar Berntsson
  • Heikki Takala
  • Kevin D Gallagher
  • Hardik Patel
  • Emil Gustavsson
  • Rachael St Peter
  • Phu Duong
  • Angela Nugent
  • Fan Zhang
  • Peter Berntsen
  • Roberto Appio
  • Ivan Rajkovic
  • Heli Lehtivuori
  • Matthijs R Panman
  • Maria Hoernke
  • Stephan Niebling
  • Rajiv Harimoorthy
  • Tilman Lamparter
  • Emina A Stojković
  • And 2 others
  • Janne A Ihalainen
  • Sebastian Westenhoff
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biochemistry and Molecular Biology
Original languageEnglish
Pages (from-to)3379-3383
JournalThe Journal of Physical Chemistry Letters
Issue number17
Publication statusPublished - 2015
Publication categoryResearch