A specific host factor binds at a cis-acting transcriptionally silent locus required for stability control of yeast plasmid pSR1.
A cis-acting locus, Z, of plasmid pSR1 functions in stable maintenance of the plasmid in the native host, Zygosaccharomyces rouxii. The Z locus was shown to be located in a 482 bp sequence in the 5' upstream region of an open reading frame, P, by subcloning various DNA fragments in a plasmid replicating via the ARS1 sequence of the Saccharomyces cerevisiae chromosome. Northern analysis revealed that the Z region is not transcribed in either the native host Z. rouxii or the heterologous host S. cerevisiae. The Z region is protected from micrococcal nuclease attack in Z. rouxii but not in S. cerevisiae, its protection depending on the product of the S gene encoded by pSR1. Gel retardation assays suggested that a factor present in nuclear extracts of Z. rouxii cells, irrespective of the presence or absence of a resident pSR1 plasmid, binds to a 111 bp RsaI-SacII sequence in the Z region. These findings suggest that a host protein binds to the Z locus and that the S product interacts with this DNA-protein complex and stabilizes pSR1.
Araki
H
H
Department of Biotechnology, Faculty of Engineering, Osaka University, Japan.
Awane
K
K
Irie
K
K
Kaisho
Y
Y
Naito
A
A
Oshima
Y
Y
D001483:Base Sequence; D015152:Blotting, Northern; D002843:Chromatin / Q000502:physiology / Q000648:ultrastructure; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D015342:DNA Probes; D004271:DNA, Fungal / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism; D010957:Plasmids; D012331:RNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D015183:Restriction Mapping; D012440:Saccharomyces / Q000235:genetics*; D014158:Transcription, Genetic
D002843:Chromatin; D015342:DNA Probes; D004271:DNA, Fungal; D009687:Nuclear Proteins; D012331:RNA, Fungal; D004247:DNA