Specific initiation of transcription at a cyanobacterial promoter with RNA polymerase purified from Calothrix sp. PCC 7601.
Although in cyanobacteria many genes have been shown to be transcriptionally controlled by specific stimuli, little is known about promoter structure and the form of RNA polymerase that recognizes individual promoters. RNA polymerase holoenzyme has been purified from Calothrix sp. PCC 7601. Its polypeptide composition resembles that of the plant chloroplast enzymes. To study transcription in cyanobacteria further, we have analysed the promoter-recognition properties of the purified enzyme. In vitro transcription was assayed with the promoter of the phycocyanin gene (cpc1) that is expressed whatever the incident light conditions. Transcription initiation at the same start point as in vivo was obtained with the Calothrix sp. PCC 7601 purified enzyme and the Escherichia coli core enzyme supplemented with a Calothrix sp. PCC 7601 sigma factor, but not with the E. coli holoenzyme.
Schyns
G
G
Physiologie Microbienne (CNRS URA 1129), Département de Biochimie et Génétique Moléculaire, Institut Pasteur, Paris, France.
Sobczyk
A
A
Tandeau de Marsac
N
N
Houmard
J
J
D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D000458:Cyanobacteria / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009876:Operon; D010798:Phycocyanin / Q000096:biosynthesis*; D010940:Plant Proteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012808:Sigma Factor / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D010940:Plant Proteins; D012808:Sigma Factor; D010798:Phycocyanin; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases