NtcA is responsible for accumulation of the small isoform of ferredoxin:NADP oxidoreductase.
In several cyanobacteria, petH, the gene encoding ferredoxin:NADP oxidoreductase (FNR), is transcribed from at least two promoters depending on growth conditions. Two transcripts (short and long) are translated from two different translation initiation sites, resulting in two isoforms (large and small, respectively). Here, we show that in Synechocystis PCC6803 the global transcriptional regulator NtcA activates transcription from the distal petH promoter. Modification of the NtcA-binding site prevents NtcA binding to the promoter in vitro and abolishes accumulation of the small isoform of FNR in vivo. We also demonstrate that a similar petH transcription and translation regime occurs in other cyanobacteria. The conditions under which this system operates provide hints for the function of each FNR isoform.
Institut de Biologie et de Technologie de Saclay, Centre National de la Recherche Scientifique and Commissariat à l'Energie Atomique, 91191 Gif-sur-Yvette, France.
Amin
A
Omairi-Nasser
Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Américo Vespucio 49, 41092 Seville, Spain.
Carla V
CV
Galmozzi
Aix-Marseille Université, Laboratoire de Chimie Bactérienne, Centre National de la Recherche Scientifique, 31 chemin J. Aiguier, 13009 Marseille, France.
Amel
A
Latifi
Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Américo Vespucio 49, 41092 Seville, Spain.
M Isabel
MI
Muro-Pastor
Institut de Biologie et de Technologie de Saclay, Centre National de la Recherche Scientifique and Commissariat à l'Energie Atomique, 91191 Gif-sur-Yvette, France.
Ghada
G
Ajlani
D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005287:Ferredoxin-NADP Reductase / Q000378:metabolism*; D005420:Flavoproteins / Q000378:metabolism*; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000378:metabolism; D046939:Synechocystis / Q000201:enzymology* / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D005420:Flavoproteins; D020033:Protein Isoforms; D014157:Transcription Factors; C075617:ntcA protein, Synechococcus; D005287:Ferredoxin-NADP Reductase; C082502:petH protein, Bacteria