Microcystins are toxins produced by cyanobacteria that entail serious health and environmental problems. They cyclic heptapeptides synthesized via a mixed polyketide synthase/non-ribosomal peptide synthetase system called microcystin synthetase. Environmental nutritional factors trigger synthesis still debated this work deals with the study of influence iron status on synthesis. The results indicate deficiency could be one inducing For first time, increased transcription an essential mcy...

Abstract Chloroplast ferredoxin (Fd) plays a pivotal role in plant cell metabolism by delivering reducing equivalents to various essential oxidoreductive pathways. Fd levels decrease under adverse environmental conditions many microorganisms, including cyanobacteria, which share common ancestor with chloroplasts. Conversely, stress situations induce the synthesis of flavodoxin (Fld), an electron carrier flavoprotein not found plants, can efficiently replace most transfer processes. We report...

Iron limitation affects one-third of the cultivable land on Earth and represents a major concern for agriculture. It causes decline many photosynthetic components, including Fe-S protein ferredoxin (Fd), involved in essential oxidoreductive pathways chloroplasts. In cyanobacteria some algae, Fd down-regulation under Fe deficit is compensated by induction an isofunctional electron carrier, flavodoxin (Fld), flavin mononucleotide-containing not found plants. Transgenic tobacco lines expressing...

The occurrence of free-living amoebae (FLA) was investigated in 83 water samples from reservoirs and treatment plants, with culture positive 64 them (77.1%). Polymerase chain reaction (PCR) partial 18S rRNA gene ITS region performed order to identify amoeba isolates, the presence Legionella pneumophila , Mycobacterium spp., Pseudomonas Microcystis aeruginosa 43 isolates by multiplex PCR. Of isolated amoebae, 31 were Acanthamoeba 21 Hartmannella vermiformis, 13 Naegleria one Vanella spp. T2,...

Knowledge on the regulatory mechanisms controlling iron homeostasis in cyanobacteria is limited. In Anabaena sp. PCC 7120, ferric uptake regulator FurA a constitutive and essential protein whose expression induced under deprivation. Our previous analyses have shown that this acts as global transcriptional regulator, of several genes belonging to different functional categories, including schT, gene coding for TonB-dependent schizokinen transporter. present study we analysed impact...

The increasing antibiotic resistance evolved by Helicobacter pylori has alarmingly reduced the eradication rates of first-line therapies. To overcome current circulating resistome, we selected a novel potential therapeutic target in order to identify new candidate drugs for treating H. infection. We screened 1120 FDA-approved molecules that bind essential response regulator HsrA and potentially inhibit its biological function. Seven natural flavonoids were identified as binders. All these...

The gene coding for flavodoxin from Anabaena PCC 7119 was cloned by using the polymerase chain reaction (PCR). is transcribed into a 1250-base transcript. expression of analysed and found to be regulated at transcriptional level availability iron. PCR-amplified vector pTrc 99b expressed in Escherichia coli. High concentrations were (20% total protein). recombinant protein purified cytosolic fraction cells it exhibited properties identical with those wild-type flavodoxin.

In the filamentous cyanobacterium Anabaena sp. PCC 7120, ferric uptake regulator FurA functions as a global transcriptional regulator. Despite several analyses have focused on elucidating FurA-regulatory network, number of target genes described for this essential transcription factor is limited to handful examples. article, we combine an in silico genome-wide predictive approach with experimental determinations better define regulon. Predicted FurA-binding sites were identified upstream 215...

Fur (ferric uptake regulator) is a prokaryotic transcriptional regulator that controls large number of genes mainly related to iron metabolism. Several homologues with different physiological roles are frequently found in the same organism. The genome filamentous cyanobacterium Anabaena (Nostoc) sp. PCC 7120 codes for three fur genes. FurA an essential protein involved homoeostasis also modulates dinitrogen fixation. interacts haem, impairing its DNA-binding ability. To explore functional...

Previous genomic analyses of the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 have identified three ferric uptake regulator (Fur) homologs with low sequence identities and probably different functions in cell. FurA is a constitutive protein that shares highest homology Fur from heterotrophic bacteria appears to be essential for vitro growth. In this study, we analysed effects overexpression on phenotype investigated which observed alterations were directly operated by...

The binding affinity of NtcA towards promoter regions the microcystin gene cluster from Microcystis aeruginosa PCC 7806 has been analyzed by band-shift assay (EMSA). key nitrogen transcriptional regulator exhibits for two fragments bidirectional mcyDA promoter, as well mcyE and mcyH. presence 2-oxoglutarate increased 2.5 fold mcyA region. effect peaked at 0.8 mM, a physiological concentration this compound under nitrogen-limiting conditions. results suggest that level, signal C to N balance...

In the nitrogen-fixing heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, ferric uptake regulator FurA plays a global regulatory role. Failures to eliminate wild-type copies of furA gene from polyploid genome suggest essential functions. present study, we developed selectively regulated expression system by replacement promoter in chromosomes with Co2+/Zn2+ inducible coaT Synechocystis 6803. By removing Co2+ and Zn2+ medium shutting off expression, showed that was absolutely required...

Haloferax mediterranei, an extreme halophilic archaeon thriving in hypersaline environments, has acquired significant attention biotechnological and biochemical research due to its remarkable ability flourish salinity conditions. Transcription factors, essential regulating diverse cellular processes, have become focal points understanding adaptability. This study delves into the role of Lrp transcription factor, exploring modulation glnA, nasABC, lrp gene promoters vivo through...