Phytoene desaturase (lycopene-forming) Phytoene desaturase (lycopene-forming) Phytoene desaturase (lycopene-forming) (CrtI, "four-step phytoene desaturase") (, "15-cis-phytoene:acceptor oxidoreductase (lycopene-forming)") are enzymes found in archaea, bacteria and fungi that are involved in carotenoid biosynthesis. They catalyze the conversion of colorless 15-"cis"-phytoene into a bright red lycopene in a biochemical pathway called the poly-trans pathway. The same process in plants and cyanobacteria utilizes four separate enzymes in a poly-cis pathway. Bacterial phytoene desaturases were shown to require FAD as a cofactor for their function. During the chemical reaction in total four additional double bonds are introduced into phytoene: In 2000 it was discovered that the gene insertion
Terry Pratchett's The Colour of Magic programming at Sky One, also appears as the Alchemist. A teaser trailer, released in late February 2008, featured principal cast members, including Rincewind, Twoflower, Trymon and the Arch-Astronomer of Krull, attempting to describe octarine, the 'colour of magic'. The teaser concludes with the film's tagline: "a pigment of your imagination". Two more trailers were released in March 2008, containing a more complete synopsis, with narration by Brian Cox. The trailers formed part of a multimillion-dollar advertising campaign in partnership with Amazon.com and Borders Books. In addition to conventional adverts in national newspapers and banner ads on sites including MSN.com and