HetR, a serine type protease, plays an important role in heterocyst differentiation in filamentous cyanobacteria. We isolated and sequenced the hetR genes from different heterocystous and filamentous nonheterocystous cyanobacteria. The hetR gene in the heterocyst forming Anabaena variabilis ATCC 29413 FD was interrupted by interposon mutagenesis (mutant strain WSIII8). This mutant does not form heterocysts and shows no diazotrophic growth under aerobic conditions. However, under anaerobic N(2)-fixing conditions, the WSIII8 cells are able to grow, and high nitrogenase (Nif2) activity is detectable. Nif2 expression was demonstrated in each vegetative cell of the filament by immunolocalization 4 h after nitrogen step-down.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0167-4781(02)00399-8 | DOI Listing |
Plant Physiol Biochem
January 2025
Laboratory of Microbial Genetics, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address:
Nitric oxide synthases (NOSs) are heme-based monooxygenases that catalyze the NADPH-dependent oxidation of L-arginine to produce NO and L-citrulline. Over the past five years, the identification and characterization of NOS homologs in cyanobacteria have significantly advanced our understanding of these enzymes. However, the precise mechanisms through which NOS-derived NO influences nitrogen metabolism remain incompletely elucidated.
View Article and Find Full Text PDFFront Microbiol
July 2024
Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
Cyanobacteria have great potential in CO-based bio-manufacturing and synthetic biological studies. The filamentous cyanobacterium, sp. strain BL0902, is comparable to () in commercial-scale cultivation while proving to be more genetically tractable.
View Article and Find Full Text PDFMol Microbiol
November 2023
Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, People's Republic of China.
The filamentous cyanobacterium Anabaena sp. PCC 7120 is able to form heterocysts for nitrogen fixation. Heterocyst differentiation is initiated by combined-nitrogen deprivation, followed by the commitment step during which the developmental process becomes irreversible.
View Article and Find Full Text PDFPLoS One
August 2023
Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Zaragoza, Spain.
FurC (PerR, Peroxide Response Regulator) from Anabaena sp. PCC 7120 (also known as Nostoc sp. PCC 7120) is a master regulator engaged in the modulation of relevant processes including the response to oxidative stress, photosynthesis and nitrogen fixation.
View Article and Find Full Text PDFPLoS Comput Biol
August 2022
Grupo Interdisciplinar de Sistemas Complejos (GISC) and Departamento de Matemáticas, Universidad Carlos III de Madrid, Leganés, Spain.
The Anabaena genus is a model organism of filamentous cyanobacteria whose vegetative cells can differentiate under nitrogen-limited conditions into a type of cell called heterocyst. These heterocysts lose the possibility to divide and are necessary for the colony because they can fix and share environmental nitrogen. In order to distribute the nitrogen efficiently, heterocysts are arranged to form a quasi-regular pattern whose features are maintained as the filament grows.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!