Jump to main content
Jump to site search

Issue 10, 2008
Previous Article Next Article

Bacterial bilin- and flavin-binding photoreceptors

Author affiliations

Abstract

The growing number of sequenced prokaryotic genomes reveals a wide distribution of open reading frames (ORFs) that putatively encode for red- and blue light sensing photoreceptors. They comprise the bilin-binding phytochromes and the flavin-binding cryptochromes, LOV and BLUF proteins, indicating that about 1/4 of bacteria do possess at least one of these photosensory proteins. The distribution of red- and blue-light sensors among different prokaryotic phyla and classes, and their functional activity as light-switched systems are the subject of this perspective. These photoreceptors were originally found in plants by following the associated physiological responses induced by the respective spectral irradiation. Genome-based approaches now require the assignment of a photochemical/physiological function to the heterologously expressed gene product. Database searches demonstrate in some cases several genes of one category in a certain prokaryot, indicating the presence of more than one type of red- or blue-light sensing properties, but also show a combination of proteins with both spectral sensitivities. Another interesting feature now “comes into light”: according to their nature as biological sensors, these photoreceptors are equipped with signalling domains, initiating a cellular response, thereby constituting modular systems switchable by light. It is seen that many of these signalling domains, now found together with light-inducible sensing domains, were already described for other stimuli, e.g., osmo-regulation, oxygen, hydrogen, chemicals, or pH. In some cases, the same type of signalling domain can be found in a red- or a blue-light sensing photoreceptor. Following the characterization of their photochemistry, for several of these bacterial photoreceptors physiological functions are now assigned.

Graphical abstract: Bacterial bilin- and flavin-binding photoreceptors

Back to tab navigation

Supplementary files

Publication details

The article was received on 13 Feb 2008, accepted on 13 Aug 2008 and first published on 05 Sep 2008


Article type: Perspective
DOI: 10.1039/B802472C
Photochem. Photobiol. Sci., 2008,7, 1168-1178

  •   Request permissions

    Bacterial bilin- and flavin-binding photoreceptors

    A. Losi and W. Gärtner, Photochem. Photobiol. Sci., 2008, 7, 1168
    DOI: 10.1039/B802472C

Search articles by author

Spotlight

Advertisements