Biosynthesis of Diapocarotene

The Heliobacteriaceae only have Cj acyclic carotenes, 4,4 -diapocarotenes, instead of the usual carotenoids (Fig. 11 Takaichi et al., 1997b). 4,4 -Diaponeurosporene is the major carotene, and diapophytoene, diapophytofluene, diapo-C-carotene and diapolycopene are also found as minor components. Two genes encoding enzymes in the early steps of diapocarotene biosynthesis have been 

Carotene glucoside ester 6 4-Keto-3 ,4 -didehydro-OH-v-carotene glucoside 

Fig 10. The predicted pathway for the biosynthesis of OH-y-carotene glucoside ester of Cfl. aurantiacus. 

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