title: Constitutive and nitrogen-regulated promoters of the petH gene encoding ferredoxin:NADP+ reductase in the heterocyst-forming cyanobacterium Anabaena sp.
abstract: Determination of the putative transcription start points of the petH gene encoding ferredoxin:NADP+ reductase in the heterocyst-forming cyanobacteria Anabaena sp. PCC 7119 and PCC 7120 showed that this gene is transcribed from two promoters, one constitutively used under different conditions of nitrogen nutrition and the other one used in cells subjected to nitrogen stepdown and in nitrogen-fixing filaments. The latter promoter, whose use was NtcA-dependent but HetR-independent, was functional in heterocysts. The N-control transcriptional regulator NtcA was observed to bind in vitro to this promoter. For the sake of comparison, the transcription start points of the nifHDK operon in strain PCC 7120 and binding of NtcA to the nifHDK promoter were also examined.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Centro de Investigaciones Científicas Isla de la Cartuja, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Valladares
authors.forename: A M
authors.initials: AM
authors.lastname: Muro-Pastor
authors.forename: M F
authors.initials: MF
authors.lastname: Fillat
authors.forename: A
authors.initials: A
authors.lastname: Herrero
authors.forename: E
authors.initials: E
authors.lastname: Flores
mesh_terms: D017033:Anabaena / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005287:Ferredoxin-NADP Reductase / Q000235:genetics*; D005420:Flavoproteins; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism*; D009591:Nitrogenase / Q000235:genetics; D010088:Oxidoreductases; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D005420:Flavoproteins; D014157:Transcription Factors; C075617:ntcA protein, Synechococcus; D010088:Oxidoreductases; D005287:Ferredoxin-NADP Reductase; C082502:petH protein, Bacteria; D009591:Nitrogenase; C029130:nitrogenase reductase; D009584:Nitrogen