Pleiotropic effects of puf interposon mutagenesis on carotenoid biosynthesis in Rubrivivax gelatinosus. A new gene organization in purple bacteria.
Rubrivivax gelatinosus mutants affected in the carotenoid biosynthesis pathways were created by interposon mutagenesis within the puf operon. Genetic and biochemical analysis of several constructed mutants suggest that at least crtC is localized downstream of the puf operon and that it is cotranscribed with this operon. Sequence analysis confirmed the genetic data and showed the presence of crtD and crtC genes downstream of the puf operon, a localization different from that known for other purple bacteria. Inactivation of the crtD gene indicated that the two crt genes are cotranscribed and that they are involved not only in the hydroxyspheroidene biosynthesis pathway as in Rhodobacter sphaeroides and R. capsulatus, but also in the spirilloxanthin biosynthesis pathway. Carotenoid genes implicated in the spirilloxanthin biosynthesis pathway were thus identified for the first time. Furthermore, analysis of carotenoid synthesis in the mutants gave genetic evidence that crtD and crtC genes are cotranscribed with the puf operon using the oxygen-regulated puf promoter.
Ouchane
S
S
Centre de Génétique Moléculaire du CNRS (UPR 9061) Associé à l'Université Pierre et Marie Curie, Bâtiment 24, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France.
Picaud
M
M
Vernotte
C
C
Reiss-Husson
F
F
Astier
C
C
D019883:Alkyl and Aryl Transferases; D000595:Amino Acid Sequence; D002338:Carotenoids / Q000378:metabolism; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D005798:Genes, Bacterial; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009876:Operon; D010088:Oxidoreductases / Q000235:genetics*; D012244:Rhodospirillaceae / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D004251:DNA Transposable Elements; D002338:Carotenoids; D010088:Oxidoreductases; C075277:methoxyneurosporene dehydrogenase; D019883:Alkyl and Aryl Transferases; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase