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Light‐induced carotenogenesis in Myxococcus xanthus : genetic analysis of the carR region
Author(s) -
Hodgson David A.
Publication year - 1993
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1993.tb01138.x
Subject(s) - myxococcus xanthus , biology , transposable element , genetics , promoter , gene , transcription (linguistics) , locus (genetics) , mutant , gene expression , linguistics , philosophy
Summary Carotenogenesis is light‐inducible in the non‐photo‐synthetic, Gram‐negative, bacterium Myxococcus xanthus. We report the characterization of the carR region which controls this phenomenon. Insertion of transposon Tn 5 close to the carR region caused a dominant, carotenoid‐constitutive mutation because of the presence of a constitutive, outward‐reading promoter in the IS 50 L component of Tn 5. 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 car A locus.