Cloning and characterisation of the pknD gene encoding an eukaryotic-type protein kinase in the cyanobacterium Anabaena sp. PCC7120

1998 ◽  
Vol 258 (1-2) ◽  
pp. 26-33 ◽  
Author(s):  
C.-C. Zhang ◽  
L. Libs
Microbiology ◽  
2003 ◽  
Vol 149 (11) ◽  
pp. 3257-3263 ◽  
Author(s):  
Jian-Hong Li ◽  
Sophie Laurent ◽  
Viren Konde ◽  
Sylvie Bédu ◽  
Cheng-Cai Zhang

In the filamentous cyanobacterium Anabaena sp. strain PCC 7120, a starvation of combined nitrogen induces differentiation of heterocysts, cells specialized in nitrogen fixation. How do filaments perceive the limitation of the source of combined nitrogen, and what determines the proportion of heterocysts? In cyanobacteria, 2-oxoglutarate provides a carbon skeleton for the incorporation of inorganic nitrogen. Recently, it has been proposed that the concentration of 2-oxoglutarate reflects the nitrogen status in cyanobacteria. To investigate the effect of 2-oxoglutarate on heterocyst development, a heterologous gene encoding a 2-oxoglutarate permease under the control of a regulated promoter was expressed in Anabaena sp. PCC 7120. The increase of 2-oxoglutarate within cells can trigger heterocyst differentiation in a subpopulation of filaments even in the presence of nitrate. In the absence of a source of combined nitrogen, it can increase heterocyst frequency, advance the timing of commitment to heterocyst development and further increase the proportion of heterocysts in a patS mutant. Here, it is proposed that the intracellular concentration of 2-oxoglutarate is involved in the determination of the proportion of the two cell types according to the carbon/nitrogen status of the filament.


FEBS Letters ◽  
1999 ◽  
Vol 449 (2-3) ◽  
pp. 159-164 ◽  
Author(s):  
Ana Valladares ◽  
Alicia M. Muro-Pastor ◽  
María F. Fillat ◽  
Antonia Herrero ◽  
Enrique Flores

2002 ◽  
Vol 184 (9) ◽  
pp. 2491-2499 ◽  
Author(s):  
Kathryn M. Jones ◽  
Robert Haselkorn

ABSTRACT Two operons have been cloned from Anabaena sp. strain PCC 7120 DNA, each of which encodes the three core subunits of distinct mitochondrial-type cytochrome c oxidases. The two operons are only 72 to 85% similar to one another at the nucleotide level in the most conserved subunit. One of these, coxBACII, is induced >20-fold in the middle to late stages of heterocyst differentiation. Analysis of green fluorescent protein reporters indicates that this operon is expressed specifically in proheterocysts and heterocysts. The other operon, coxBACI, is induced only 2.5-fold following nitrogen step-down and is expressed in all cells. Surprisingly, a disruption mutant of coxAII, the gene encoding subunit I of the heterocyst-specific oxidase, grows normally in the absence of combined nitrogen. It is likely that coxBACI and/or two other putative terminal oxidases present in the Anabaena sp. strain PCC 7120 genome are able to compensate for the loss of the heterocyst-specific oxidase in providing ATP for nitrogen fixation and maintaining a low oxygen level in heterocysts.


1992 ◽  
Vol 19 (3) ◽  
pp. 491-492 ◽  
Author(s):  
Arnaud Bovy ◽  
Geert de Vrieze ◽  
Mies Borrias ◽  
Peter Weisbeek

Author(s):  
Patrick Videau ◽  
Kaitlyn Wells ◽  
Arun Singh ◽  
Jessie Eiting ◽  
Philip Proteau ◽  
...  

Cyanobacteria are prolific producers of natural products and genome mining has shown that many orphan biosynthetic gene clusters can be found in sequenced cyanobacterial genomes. New tools and methodologies are required to investigate these biosynthetic gene clusters and here we present the use of <i>Anabaena </i>sp. strain PCC 7120 as a host for combinatorial biosynthesis of natural products using the indolactam natural products (lyngbyatoxin A, pendolmycin, and teleocidin B-4) as a test case. We were able to successfully produce all three compounds using codon optimized genes from Actinobacteria. We also introduce a new plasmid backbone based on the native <i>Anabaena</i>7120 plasmid pCC7120ζ and show that production of teleocidin B-4 can be accomplished using a two-plasmid system, which can be introduced by co-conjugation.


BIO-PROTOCOL ◽  
2016 ◽  
Vol 6 (15) ◽  
Author(s):  
Kangming Chen ◽  
Huilan Zhu ◽  
Liping Gu ◽  
Shengni Tian ◽  
Ruanbao Zhou

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