Jaubert Marianne, Lavergne J., Fardoux Joel, Hannibal Laure, Vuillet Laurie, Adriano J. M., Bouyer P., Pignol D., Giraud Eric, Vermeglio A. (2007). A singular bacteriophytochrome acquired by lateral gene transfer. Journal of Biological Chemistry, 282 (10), p. 7320-7328. ISSN 0021-9258.
Titre du document
A singular bacteriophytochrome acquired by lateral gene transfer
Jaubert Marianne, Lavergne J., Fardoux Joel, Hannibal Laure, Vuillet Laurie, Adriano J. M., Bouyer P., Pignol D., Giraud Eric, Vermeglio A.
Source
Journal of Biological Chemistry, 2007,
282 (10), p. 7320-7328 ISSN 0021-9258
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.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Biotechnologies [084]
