title: Possible involvement of ActVI-ORFA in transcriptional regulation of actVI tailoring-step genes for actinorhodin biosynthesis.
abstract: The actinorhodin biosynthetic gene (act) cluster in Streptomyces coelicolor carries a functionally unknown gene, actVI-ORFA. We have characterized an ActVI-ORFA disruptant by functional complementation and reverse transcriptase polymerase chain reaction analysis of the expression profiles of the act genes. Introduction of the functional actVI-ORFA gene into the disruptant restored actinorhodin production to an extent similar to that seen in the wild-type cells and abolished the accumulation of actinorhodin biosynthetic intermediates and shunt products specific for actVI mutants. Thus, unique phenotypes observed in the mutant are solely dependent on the function of actVI-ORFA. The disruptant was shown to yield significantly lower levels of the transcripts for certain act genes, especially for the actVI-ORF1-VA-ORF2 transcription unit, leading to the accumulation of the intermediates and shunt products. The functional actVI-ORFA gene restored expression of actVI-ORF1, which encodes a key reductase in the actinorhodin tailoring step, in the mutant cells, indicating a possible regulatory role of ActVI-ORFA.
authors.affiliation: Research Institute of Pharmaceutical Sciences, Musashino University, Shinmachi, Nishitokyo-shi, Tokyo, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Taguchi
authors.forename: Susumu
authors.initials: S
authors.lastname: Okamoto
authors.forename: Alexander
authors.initials: A
authors.lastname: Lezhava
authors.forename: Aiying
authors.initials: A
authors.lastname: Li
authors.forename: Kozo
authors.initials: K
authors.lastname: Ochi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ebizuka
authors.forename: Koji
authors.initials: K
authors.lastname: Ichinose
mesh_terms: D000880:Anthraquinones / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005810:Multigene Family; D009154:Mutation; D016366:Open Reading Frames; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D000095622:Benzoisochromanequinones
chemical_list: D000880:Anthraquinones; D001426:Bacterial Proteins; D003470:Culture Media; C013390:actinorhodin; D000095622:Benzoisochromanequinones