Bacteriophytochromes: new tools for understanding phytochrome signal transduction

Semin Cell Dev Biol. 2000 Dec;11(6):511-21. doi: 10.1006/scdb.2000.0206.


The recent discovery of phytochrome-like photoreceptors, collectively called bacteriophytochromes, in a number of bacteria has greatly expanded our understanding of the origins and modes of action of phytochromes in higher plants. These primitive receptors contain an N-terminal domain homologous to the chromophore-binding pocket of phytochromes, and like phytochromes, they bind a variety of bilins to generate photochromic holoproteins. Following the chromophore pocket is a domain similar to two-component histidine kinases, suggesting that these bacterial photoreceptors function in phosphorelay cascades that respond to the light environment. Their organization and distribution support the views that higher-plant phytochromes evolved from a cyanobacterial precursor and that they act as light-regulated kinases. With the ability to exploit bacterial genetics, these bacteriophytochromes now offer simple models to help unravel the biochemical and biophysical events that initiate phytochrome signal transmission.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Evolution, Molecular
  • Histidine Kinase
  • Light
  • Light-Harvesting Protein Complexes*
  • Molecular Sequence Data
  • Photoreceptors, Microbial
  • Photosynthetic Reaction Center Complex Proteins / metabolism
  • Phytochrome / chemistry
  • Phytochrome / metabolism*
  • Protein Kinases / chemistry
  • Protein Kinases / metabolism
  • Sequence Alignment
  • Signal Transduction*


  • Bacterial Proteins
  • Light-Harvesting Protein Complexes
  • Photoreceptors, Microbial
  • Photosynthetic Reaction Center Complex Proteins
  • RcaE protein, cyanobacteria
  • Phytochrome
  • Protein Kinases
  • Histidine Kinase
  • CikA protein, bacteria
  • Cph1 phytochrome protein, bacteria
  • plpA protein, Synechocystis sp. PCC 6803