The circadian clock in the prokaryote Synechococcus RF-1
Article Abstract:
The unicellular cyanobacterium Synechococcus RF-1 exhibits a circadian rhythm during nitrogen fixation. The circadian rhythms of nitrogenase activity are regulated by the oscillator in Synechococcus under continuously illuminated and aerobic conditions. A diurnal light/dark (L/D) regimen that changes the duration of light and darkness activates the circadian nitrogenase activity. Nitrogen fixations occurs at a high rate under such a regimen, during the dark periods. Experimental studies of the circadian rhythmic nif gene expression indicates a transcriptional level regulation of the nitrogenase activity rhythm.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1995
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Inducible expression of heterologous genes targeted to a chromosomal platform in the cyanobacterium Synechococcus sp. PCC 7942
Article Abstract:
Escherichia coli trc promoter and lacl repressor were used to obtain high-level, inducible expression of heterologous genes in the cyanobacterium Synechococcus sp. strain PCC 7942. Beta-glucuronidase acts as reporter in the determination of the influence of IPTG concentration and gene expression induction time with E. coli trc/lac system in Synechococcus. The induction with IPTG expressed Anabaena PCC 7937 petE gene to a higher level. Cyanobacteria have a simple structure, yet are able to go through oxygenic photosynthesis similar to that of more complex chloroplasts.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1995
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Organization and expression of nitrogen-fixation genes in the aerobic nitrogen-fixing unicellular cyanobacterium Synechococcus sp. strain RF-1
Article Abstract:
Sixteen nif and nif-related genes in Synechococcus sp. strain Rf-1 were cloned and sequenced. All of the nif and nif-related genes were organized in a continuous cluster spanning about 18 kb and containing seven operons. The nifH operon has been previously reported. The nifB, fdxN, nifS, nifU and nifP were localized upstream of the nifH operon. A nifP-like gene was localized just upstream of nifB. The genes nifE, nifN, nifX, nifW and the nif-related hesA, hesB and fdx were located downstream from nifK.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1999
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