Search results for "stigmate"
showing 3 items of 3 documents
Coordination of the biliverdin D-ring in bacteriophytochromes.
2018
Phytochrome proteins translate light into biochemical signals in plants, fungi and microorganisms. Light cues are absorbed by a bilin chromophore, leading to an isomerization and a rotation of the D-ring. This relays the signal to the protein matrix. A set of amino acids, which is conserved across the phytochrome superfamily, holds the chromophore in the binding pocket. However, the functional role of many of these amino acids is not yet understood. Here, we investigate the hydrogen bonding network which surrounds the D-ring of the chromophore in the resting (Pr) state. We use UV/vis spectroscopy, infrared absorption spectroscopy and X-ray crystallography to compare the photosensory domains…
Structural basis for light control of cell development revealed by crystal structures of a myxobacterial phytochrome
2018
Phytochromes are red-light photoreceptors that were first characterized in plants, with homologs in photosynthetic and non-photosynthetic bacteria known as bacteriophytochromes (BphPs). Upon absorption of light, BphPs interconvert between two states denoted Pr and Pfr with distinct absorption spectra in the red and far-red. They have recently been engineered as enzymatic photoswitches for fluorescent-marker applications in non-invasive tissue imaging of mammals. This article presents cryo- and room-temperature crystal structures of the unusual phytochrome from the non-photosynthetic myxobacterium Stigmatella aurantiaca (SaBphP1) and reveals its role in the fruiting-body formation of this ph…
De la conscience fière au stigmate social : le virilisme ouvrier à l’épreuve des années 1968
2014
La masculinité ouvrière, en tant que caractère(s) du masculin, ressortit, on le sait, au virilisme : l’exhibition du corps fort liée à la dureté du travail, une manière d’exacerbation de la masculinité, relèvent de la culture ouvrière. Dès lors, le virilisme désignerait en première approche une forme d’ostentation de la virilité, qui en vient à faire système : non pas seulement l’exaltation de vertus masculines supposées – force, courage, endurance, etc., mais aussi réflexion, sagacité, etc. ...