Read by QxMD icon Read

Anabaena sp.PCC 7120

Akiyoshi Higo, Atsuko Isu, Yuki Fukaya, Toru Hisabori
In recent years, studies on the development of gene regulation tools in cyanobacteria have been extensively conducted towards efficient production of valuable chemicals. However, there is considerable scope for improving the economic feasibility of production. To improve a recently reported gene induction system using anhydrotetracycline (aTc)-TetR and an endogenous gene repression system using small antisense RNA in the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 (Anabaena), we constructed a positive feedback loop, in which gfp and a small antisense RNA for tetR are controlled by an aTc-inducible promoter...
September 16, 2016: ACS Synthetic Biology
Sergey Kosourov, Gayathri Murukesan, Jouni Jokela, Yagut Allahverdiyeva
The carotenoid composition of the filamentous heterocystous N2-fixing cyanobacterium Calothrix sp. 336/3 was investigated under three conditions: in full medium (non-diazotrophic growth); in the absence of combined nitrogen (diazotrophic growth); and after long-term H2 photoproduction (diazotrophic medium and absence of nitrogen in atmosphere). Anabaena sp. PCC 7120 and its ΔhupL mutant with disrupted uptake hydrogenase were used as reference strains. Analysis of identified carotenoids and enzymes involved in carotenogenesis showed the presence of three distinct biosynthetic pathways in Calothrix sp...
August 12, 2016: Plant & Cell Physiology
Balkrishna Tiwari, Sindhunath Chakraborty, Savita Singh, Arun K Mishra
To understand the mechanism underlying organophosphate pesticide toxicity, cyanobacterium Anabaena PCC 7120 was subjected to varied concentrations (0, 5, 10, 20 and 30 mg L(-1)) of profenofos and the effects were investigated in terms of changes in cellular physiology, genomic template stability and protein expression pattern. The supplementation of profenofos reduced the growth, total pigment content and photosynthetic efficiency of the test organism in a dose dependent manner with maximum toxic effect at 30 mg L(-1)...
November 2016: Journal of Environmental Science and Health. Part. B, Pesticides, Food Contaminants, and Agricultural Wastes
Javier Santamaría-Gómez, Jesús A G Ochoa de Alda, Elvira Olmedo-Verd, Roque Bru-Martínez, Ignacio Luque
tRNAs are charged with cognate amino acids by aminoacyl-tRNA synthetases (aaRSs) and subsequently delivered to the ribosome to be used as substrates for gene translation. Whether aminoacyl-tRNAs are channeled to the ribosome by transit within translational complexes that avoid their diffusion in the cytoplasm is a matter of intense investigation in organisms of the three domains of life. In the cyanobacterium Anabaena sp. PCC 7120, the valyl-tRNA synthetase (ValRS) is anchored to thylakoid membranes by means of the CAAD domain...
2016: Frontiers in Microbiology
Mareike Rudolf, Mara Stevanovic, Chana Kranzler, Rafael Pernil, Nir Keren, Enrico Schleiff
Many cyanobacteria secrete siderophores to sequester iron. Alternatively, mechanisms to utilize xenosiderophores have evolved. The overall uptake systems are comparable to that of other bacteria involving outer membrane transporters energized by TonB as well as plasma membrane-localized transporters. However, the function of the bioinformatically-inferred components is largely not established and recent studies showed a high diversity of the complexity of the uptake systems in different cyanobacteria. Thus, we approached the systems of the filamentous Anabaena sp...
September 2016: Plant Molecular Biology
Caroline Chénard, Jennifer F Wirth, Curtis A Suttle
UNLABELLED: Here we present the first genomic characterization of viruses infecting Nostoc, a genus of ecologically important cyanobacteria that are widespread in freshwater. Cyanophages A-1 and N-1 were isolated in the 1970s and infect Nostoc sp. strain PCC 7210 but remained genomically uncharacterized. Their 68,304- and 64,960-bp genomes are strikingly different from those of other sequenced cyanophages. Many putative genes that code for proteins with known functions are similar to those found in filamentous cyanobacteria, showing a long evolutionary history in their host...
2016: MBio
M A Radtsig, O A Koksharova, V A Nadtochenko, I A Khmel
Diazotrophic cyanobacteria Anabaena sp. PCC 7120, four Nostoc strains, and two Azotobacter species (A. vinelandii and A. chroococcum) were found to produce gold nanoparticles (GNP) under nitrogen fixation conditions. GNP biogenesis occurred at AuHCl₄ concentrations from 0.1 to 1 mM. In the cultures of unicellular cyanobacteria Synechococcus sp. PCC 7942 and Synechocystis incapable of nitrogen fixation, no GNP were formed at the same concentrations of gold salts. The plasmon resonance band peak was located at 552 nm...
January 2016: Mikrobiologiia
Vicente Mariscal, Dennis J Nürnberg, Antonia Herrero, Conrad W Mullineaux, Enrique Flores
Filamentous, N2 -fixing, heterocyst-forming cyanobacteria grow as chains of cells that are connected by septal junctions. In the model organism Anabaena sp. strain PCC 7120, the septal protein SepJ is required for filament integrity, normal intercellular molecular exchange, heterocyst differentiation, and diazotrophic growth. An Anabaena strain overexpressing SepJ made wider septa between vegetative cells than the wild type, which correlated with a more spread location of SepJ in the septa as observed with a SepJ-GFP fusion, and contained an increased number of nanopores, the septal peptidoglycan perforations that likely accommodate septal junctions...
September 2016: Molecular Microbiology
Reza Dastvan, Eva-Maria Brouwer, Denise Schuetz, Oliver Mirus, Enrico Schleiff, Thomas F Prisner
Many proteins of the outer membrane of Gram-negative bacteria and of the outer envelope of the endosymbiotically derived organelles mitochondria and plastids have a β-barrel fold. Their insertion is assisted by membrane proteins of the Omp85-TpsB superfamily. These proteins are composed of a C-terminal β-barrel and a different number of N-terminal POTRA domains, three in the case of cyanobacterial Omp85. Based on structural studies of Omp85 proteins, including the five POTRA-domain-containing BamA protein of Escherichia coli, it is predicted that anaP2 and anaP3 bear a fixed orientation, whereas anaP1 and anaP2 are connected via a flexible hinge...
May 24, 2016: Biophysical Journal
Rocío López-Igual, Adjélé Wilson, Ryan L Leverenz, Matthew R Melnicki, Céline Bourcier de Carbon, Markus Sutter, Aiko Turmo, François Perreau, Cheryl A Kerfeld, Diana Kirilovsky
The photoactive Orange Carotenoid Protein (OCP) is involved in cyanobacterial photoprotection. Its N-terminal domain (NTD) is responsible for interaction with the antenna and induction of excitation energy quenching, while the C-terminal domain is the regulatory domain that senses light and induces photoactivation. In most nitrogen-fixing cyanobacterial strains, there are one to four paralogous genes coding for homologs to the NTD of the OCP. The functions of these proteins are unknown. Here, we study the expression, localization, and function of these genes in Anabaena sp...
July 2016: Plant Physiology
Tylor J Johnson, Jacob D Zahler, Emily L Baldwin, Ruanbao Zhou, William R Gibbons
Cyanobacteria are currently being engineered to photosynthetically produce next-generation biofuels and high-value chemicals. Many of these chemicals are highly toxic to cyanobacteria, thus strains with increased tolerance need to be developed. The volatility of these chemicals may necessitate that experiments be conducted in a sealed environment to maintain chemical concentrations. Therefore, carbon sources such as NaHCO3 must be used for supporting cyanobacterial growth instead of CO2 sparging. The primary goal of this study was to determine the optimal initial concentration of NaHCO3 for use in growth trials, as well as if daily supplementation of NaHCO3 would allow for increased growth...
July 2016: Journal of Microbiological Methods
Patrick Videau, Kaitlyn N Wells, Arun J Singh, William H Gerwick, Benjamin Philmus
Cyanobacteria are well-known producers of natural products of highly varied structure and biological properties. However, the long doubling times, difficulty in establishing genetic methods for marine cyanobacteria, and low compound titers have hindered research into the biosynthesis of their secondary metabolites. While a few attempts to heterologously express cyanobacterial natural products have occurred, the results have been of varied success. Here, we report the first steps in developing the model freshwater cyanobacterium Anabaena sp...
September 16, 2016: ACS Synthetic Biology
Julia Walter, Fiona Lynch, Natalia Battchikova, Eva-Mari Aro, Peter J Gollan
Calcium is integral to the perception, communication and adjustment of cellular responses to environmental changes. However, the role of Ca(2+) in fine-tuning cellular responses of wild-type cyanobacteria under favourable growth conditions has not been examined. In this study, extracellular Ca(2+) has been altered, and changes in the whole transcriptome of Anabaena sp. PCC 7120 have been evaluated under conditions replete of carbon and combined nitrogen. Ca(2+) induced differential expression of many genes driving primary cellular metabolism, with transcriptional regulation of carbon- and nitrogen-related processes responding with opposing trends...
June 2016: Journal of Experimental Botany
Hongjie Qin, Chengrong Peng, Yongding Liu, Dunhai Li
Stratospheric ozone depletion increases the amount of ultraviolet-B radiation (UVBR) (280-320 nm) reaching the surface of the earth, potentially affecting phytoplankton. In this work, Anabaena sp. PCC 7120, a typically nitrogen (N)-fixing filamentous bloom-forming cyanobacterium in freshwater, was individually cultured in N-deficient and N-enriched media for long-term acclimation before being subjected to ultraviolet-B (UVB) exposure experiments. Results suggested that the extent of breakage in the filaments induced by UVBR increases with increasing intensity of UVB stress...
June 2012: Journal of Phycology
Andrés González, M Teresa Bes, M Luisa Peleato, María F Fillat
In the nitrogen-fixing heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, the ferric uptake regulator FurA plays a global regulatory role. Failures to eliminate wild-type copies of furA gene from the polyploid genome suggest essential functions. In the present study, we developed a selectively regulated furA expression system by the replacement of furA promoter in the Anabaena sp. chromosomes with the Co2+/Zn2+ inducible coaT promoter from Synechocystis sp. PCC 6803. By removing Co2+ and Zn2+ from the medium and shutting off furA expression, we showed that FurA was absolutely required for cyanobacterial growth...
2016: PloS One
Brenda S Pratte, Teresa Thiel
The cyanobacterium Anabaena variabilis has two Mo-nitrogenases that function under different environmental conditions in different cell types. The heterocyst-specific nitrogenase encoded by the large nif1 gene cluster and the similar nif2 gene cluster that functions under anaerobic conditions in vegetative cells are under the control of the promoter for the first gene of each cluster, nifB1 or nifB2 respectively. Associated with each of these clusters is a putative regulatory gene called cnfR (patB) whose product has a C-terminal HTH domain and an N-terminal ferredoxin-like domain...
June 2016: Molecular Microbiology
Dinka Mandakovic, Carla Trigo, Derly Andrade, Brenda Riquelme, Gabriela Gómez-Lillo, Katia Soto-Liebe, Beatriz Díez, Mónica Vásquez
Cell division in bacteria has been studied mostly in Escherichia coli and Bacillus subtilis, model organisms for Gram-negative and Gram-positive bacteria, respectively. However, cell division in filamentous cyanobacteria is poorly understood. Here, we identified a novel protein, named CyDiv (Cyanobacterial Division), encoded by the all2320 gene in Anabaena sp. PCC 7120. We show that CyDiv plays a key role during cell division. CyDiv has been previously described only as an exclusive and conserved hypothetical protein in filamentous cyanobacteria...
2016: Frontiers in Microbiology
Patrick Videau, Orion S Rivers, Blake Ushijima, Reid T Oshiro, Min Joo Kim, Benjamin Philmus, Loralyn M Cozy
UNLABELLED: To stabilize cellular integrity in the face of environmental perturbations, most bacteria, including cyanobacteria, synthesize and maintain a strong, flexible, three-dimensional peptidoglycan lattice. Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium capable of differentiating morphologically distinct nitrogen-fixing heterocyst cells in a periodic pattern. While heterocyst development has been shown to require proper peptidoglycan remodeling, the role of peptidoglycan synthesis has remained unclear...
April 2016: Journal of Bacteriology
Xue-Ping Wang, Yong-Liang Jiang, Ya-Nan Dai, Wang Cheng, Yuxing Chen, Cong-Zhao Zhou
Formation of the heterocyst envelope polysaccharide (HEP) is a key process for cyanobacterial heterocyst differentiation. The maturation of HEP in Anabaena sp. strain PCC 7120 is controlled by a gene cluster termed HEP island in addition to an operon alr3698-alr3699, which encodes two putative proteins termed Alr3698/HepD and Alr3699/HepE. Here we report the crystal structures of HepE in the apo-form and three complex forms that bind to UDP-glucose (UDPG), UDP&glucose, and UDP, respectively. The overall structure of HepE displays a typical GT-B fold of glycosyltransferases, comprising two separate β/α/β Rossmann-fold domains that form an inter-domain substrate-binding crevice...
May 2016: Glycobiology
Hanwen Diao, Chong Zhang, Shuicheng Wang, Fengxia Lu, Zhaoxin Lu
Lipoxygenase from Anabaena sp. PCC 7120 (Ana-LOX) was thermally unstable. So, improving the thermostability of the enzyme was quite essential. The target site of Ana-LOX selected for site-directed mutagenesis was based on computer-aided rational design. The thermostability and specific activity of Ana-LOX were improved with replacing valine with alanine at the target site 421 and the site 40. Compared to the wild-type enzyme which has a half-life (T 1/2) of inactivation of 3.8 min at 50 °C, the T 1/2 of mutant enzymes with V421A and V40A substitution increased to 4...
April 2016: Applied Biochemistry and Biotechnology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"