Clustering and co‐ordinated activation of carotenoid genes inMyxococcus xanthusby blue light

摘要

SummaryBlue light activates carotenoid production in the non‐photosynthetic, Gram‐negative bacteriumMyxococcus xanthus.Light is known to stimulate the expression of two unlinked genes for carotenoid synthesis,carBandcarC, through a mechanism in which the regulatory genescarA, carQandcarRtake part. GenescarQandcarRare linked together at a separate locus, whereascarAis linked tocarB.We have introduced Tn5 at various sites betweencarAandcarB.Chemical analyses of the mutant strains demonstrate the presence in this region of a cluster of genes for carotenoid synthesis. Gene expression analysis strongly argues for most (or all) of the genes in the cluster being transcribed from a single, light‐inducible promoter under the control of genescarA, carQan