Light-induced carotenogenesis in Myxococcus xanthus: genetic analysis of the carR region.
Carotenogenesis is light-inducible in the non-photosynthetic, Gram-negative, bacterium Myxococcus xanthus. We report the characterization of the carR region which controls this phenomenon. Insertion of transposon Tn5 close to the carR region caused a dominant, carotenoid-constitutive mutation because of the presence of a constitutive, outward-reading promoter in the IS50L component of Tn5. In wild-type cells, a powerful, tightly-regulated, light-inducible promoter directs the transcription of two genetic functions. One of these functions is to activate transcription of the genetically unlinked carB gene, which is involved in carotenoid synthesis. The second function (carR) regulates the light-inducible promoter. We also report the mapping of two carotenoid constitutive mutations to the previously characterized carA locus.
Department of Biological Sciences, University of Warwick, West Midlands, UK.
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Hodgson
D000483:Alleles; D002338:Carotenoids / Q000096:biosynthesis* / Q000378:metabolism; D003001:Cloning, Molecular; D004260:DNA Repair; D004251:DNA Transposable Elements; D005785:Gene Conversion; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D008027:Light; D008957:Models, Genetic; D016254:Mutagenesis, Insertional; D016941:Myxococcus xanthus / Q000235:genetics* / Q000528:radiation effects; D010088:Oxidoreductases / Q000235:genetics; D011401:Promoter Regions, Genetic; D011995:Recombination, Genetic; D015183:Restriction Mapping; D014158:Transcription, Genetic
D004251:DNA Transposable Elements; D002338:Carotenoids; C100185:(all-E) phytoene; D010088:Oxidoreductases; C022398:phytoene dehydrogenase