Autogenous transcriptional activation of a thiostrepton-induced gene in Streptomyces lividans.
Although the antibiotic thiostrepton is best known as an inhibitor of protein synthesis, it also, at extremely low concentrations (< 10(-9) M), induces the expression of a regulon of unknown function in certain Streptomyces species. Here, we report the purification of a Streptomyces lividans thiostrepton-induced transcriptional activator protein, TipAL, whose N-terminus is similar to a family of eubacterial regulatory proteins represented by MerR. TipAL was first purified from induced cultures of S.lividans as a factor which bound to and activated transcription from its own promoter. The tipAL gene was overexpressed in Escherichia coli and TipAL protein purified in a single step using a thiostrepton affinity column. Thiostrepton enhanced binding of TipAL to the promoter and catalysed specific transcription in vitro. TipAS, a second gene product of the same open reading frame consisting of the C-terminal domain of TipAL, is apparently translated using its own in-frame initiation site. Since it is produced in large molar excess relative to TipAL after induction and also binds thiostrepton, it may competitively modulate transcriptional activation.
Holmes
D J
DJ
Institut Pasteur, Paris, France.
Caso
J L
JL
Thompson
C J
CJ
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011485:Protein Binding; D012329:RNA, Bacterial; D017421:Sequence Analysis; D013302:Streptomyces / Q000187:drug effects / Q000235:genetics*; D013883:Thiostrepton / Q000494:pharmacology*; D015534:Trans-Activators / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D012329:RNA, Bacterial; C082535:TipAL protein, Streptomyces; D015534:Trans-Activators; D014157:Transcription Factors; C082536:tipAS protein, Streptomyces; D013883:Thiostrepton