%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Jaubert, Marianne
%A Lavergne, J.
%A Fardoux, Joel
%A Hannibal, Laure
%A Vuillet, Laurie
%A Adriano, J. M.
%A Bouyer, P.
%A Pignol, D.
%A Giraud, Eric
%A Vermeglio, A.
%T A singular bacteriophytochrome acquired by lateral gene transfer
%D 2007
%L fdi:010069205
%G ENG
%J Journal of Biological Chemistry
%@ 0021-9258
%M ISI:000245080900043
%N 10
%P 7320-7328
%R 10.1074/jbc.M611173200
%U https://www.documentation.ird.fr/hor/fdi:010069205
%V 282
%W Horizon (IRD)
%X Bacteriophytochromes are phytochrome-like proteins that mediate photosensory responses in various bacteria according to their light environment. The genome of the photosynthetic and plant-symbiotic Bradyrhizobium sp. strain ORS278 revealed the presence of a genomic island acquired by lateral transfer harboring a bacteriophytochrome gene, BrBphP3.ORS278, and genes involved in the synthesis of phycocyanobilin and gas vesicles. The corresponding protein BrBphP3.ORS278 is phylogenetically distant from the other (bacterio)phytochromes described thus far and displays a series of unusual properties. It binds phycocyanobilin as a chromophore, a unique feature for a bacteriophytochrome. Moreover, its C-terminal region is short and displays no homology with any known functional domain. Its dark-adapted state absorbs maximally around 610 nm, an unusually short wavelength for (bacterio)phytochromes. This form is designated as Po for orange-absorbing form. Upon illumination, a photo-reversible switch occurs between the Po form and a red (670 nm)-absorbing form (Pr), which rapidly back-reacts in the dark. Because of this instability, illumination results in a mixture of the Po and Pr states in proportions that depend on the intensity. These uncommon features suggest that BrBphP3.ORS278 could be fitted to measure light intensity rather than color.
%$ 084 ; 020