Talk:Phytochrome

The images appear to be at a early level of phytochrom research - indeed the conformations of the pigment during photoisomerization are more or less known. There appears to be a rotation of the D-ring of the tetrapyrrole, a E/Z-isomerisation at the C15-C16 double bond. There have been experiments with synthetic sterically locked pigments to characterise their conformational states. Pfr structure is still partly hypothetical though. Look for the Review Articles by Rockwell in Annu. Rev. of Plant Biol of 2006 and 2008.I uploaded updated images to german wikipedia, maybe you want to use these. --[[Special:Contributions/85.178.47.222|85.178.47.222]] ([[User talk:85.178.47.222|talk]]) 12:34, 28 May 2008 (UTC)

The images appear to be at a early level of phytochrom research - indeed the conformations of the pigment during photoisomerization are more or less known. There appears to be a rotation of the D-ring of the tetrapyrrole, a E/Z-isomerisation at the C15-C16 double bond. There have been experiments with synthetic sterically locked pigments to characterise their conformational states. Pfr structure is still partly hypothetical though. Look for the Review Articles by Rockwell in Annu. Rev. of Plant Biol of 2006 and 2008.I uploaded updated images to german wikipedia, maybe you want to use these. --[[Special:Contributions/85.178.47.222|85.178.47.222]] ([[User talk:85.178.47.222|talk]]) 12:34, 28 May 2008 (UTC)

:the chemistry and geometry of the bilin chromophore in the phytochrome family is well established in the meantime. chemically, it's biliverdin and attached to a conserved Cys residue close to the N-terminus of the PAS domain in bacteriophytochromes, whereas in Cph1 and related cyanobacterial phytochromes it's phycocyanobilin and in plants it's phytochromobilin, in both cases attached to a conserved Cys in the GAF domain. the geometries of the Pr and Pfr states are also now well established as ''ZZZssa'' and ''ZZEssa'', respectively. thus in both cases the nitrogens of rings A, B and C point towards each other, while the D ring nitrogen points outwards in Pr, flipping over to point in roughly the same direction as ring B in Pfr. however, whereas rings A-C are roughly in the same plane, in both states the D ring is significantly tilted and α-facial relative to the A-C ring plane.

:[[User:Photochrom|Photochrom]] ([[User talk:Photochrom|talk]]) 19:35, 26 April 2026 (UTC)