title: 2-oxoglutarate enhances NtcA binding activity to promoter regions of the microcystin synthesis gene cluster.
abstract: The binding affinity of NtcA towards promoter regions of the microcystin gene cluster from Microcystis aeruginosa PCC 7806 has been analyzed by band-shift assay (EMSA). The key nitrogen transcriptional regulator exhibits affinity for two fragments of the bidirectional mcyDA promoter, as well as for promoter regions of mcyE and mcyH. The presence of 2-oxoglutarate increased by 2.5 fold the affinity of NtcA for the mcyA promoter region. The 2-oxoglutarate effect peaked at 0.8 mM, a physiological concentration for this compound under nitrogen-limiting conditions. The results suggest that the 2-oxoglutarate level, as a signal of the C to N balance of the cells, regulates the microcystin gene cluster.
authors: Departamento de Bioquimica y Biologia Molecular y Celular, Facultad de Ciencias and BIFI, Unidad Asociada Rocasolano (CSIC), Universidad de Zaragoza, Zaragoza, Spain.
authors: Taís M
authors: TM
authors: Kuniyoshi
authors: Andres
authors: A
authors: Gonzalez
authors: Sara
authors: S
authors: Lopez-Gomollon
authors: Ana
authors: A
authors: Valladares
authors: M Teresa
authors: MT
authors: Bes
authors: Maria F
authors: MF
authors: Fillat
authors: M Luisa
authors: ML
authors: Peleato
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D002244:Carbon / Q000378:metabolism; D007656:Ketoglutaric Acids / Q000494:pharmacology*; D052998:Microcystins / Q000096:biosynthesis*; D046931:Microcystis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000187:drug effects / Q000235:genetics*; D009584:Nitrogen / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects* / Q000235:genetics*; D011485:Protein Binding / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D007656:Ketoglutaric Acids; D052998:Microcystins; D002244:Carbon; C078588:microcystin; D009584:Nitrogen