Phytochromes and bacterial sensor proteins are related by structural and functional homologies. Hypothesis on phytochrome-mediated signal-transduction

FEBS Lett. 1991 Apr 9;281(1-2):245-9. doi: 10.1016/0014-5793(91)80403-p.


Phytochrome and bacterial sensor proteins are related by functional and structural homologies. They are both sensors of environmental stimuli and share structural homologies which comprise a domain of about 250 amino acids (about 28 kg.mol-1). This domain is C-terminal in phytochromes and in several bacterial sensor proteins. In both groups of sensors this domain undergoes conformational changes which are caused by the N-terminal part sensing the stimulus. In the case of bacterial sensors, the conformational alteration is, regulated by additional proteins, conferred to a corresponding regulator protein which then acts on transcription. The coincidences between the two groups of sensors are striking enough to assume phytochrome to transduce signals in a way comparable to the bacterial two-component systems.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins* / chemistry
  • Bacterial Proteins* / genetics
  • Gene Library
  • Molecular Sequence Data
  • Phytochrome* / chemistry
  • Phytochrome* / genetics
  • Protein Conformation
  • Sequence Homology, Nucleic Acid
  • Signal Transduction*
  • Software


  • Bacterial Proteins
  • Phytochrome