[This corrects the article DOI: 10.1371/journal.pone.0119107.].

Cyanobacteria have shaped the earth's biosphere as the first oxygenic photoautotrophs and still play an important role in many ecosystems. The ability to adapt to changing environmental conditions is an essential characteristic in order to ensure survival. To this end, numerous studies have shown that bacteria use protein post-translational modifications such as Ser/Thr/Tyr phosphorylation in c...

Small regulatory RNAs (sRNAs) function as transcriptional and post-transcriptional regulators of gene expression in organisms from all domains of life. Cyanobacteria are thought to have developed a complex RNA-based regulatory mechanism. In the current study, by genome-wide analysis of differentially expressed small RNAs in Synechocystis sp. PCC 6803 under high light conditions, we discovered a...

We have studied the effect of the 3' terminal CCA sequence in precursors of tRNAs on catalysis by the RNase P RNA or the holoenzyme from the cyanobacterium Synechocystis sp. PCC 6803 in a completely homologous system. We have found that the absence of the 3' terminal CCA is not detrimental to activity, which is in sharp contrast to what is known in other bacterial systems. We have found that th...

Copper is an essential element involved in fundamental processes like respiration and photosynthesis. However, it becomes toxic at high concentration, which has forced organisms to control its cellular concentration. We have recently described a copper resistance system in the cyanobacterium Synechocystis sp. PCC 6803, which is mediated by the two-component system, CopRS, a RND metal transport ...

A universal structural feature of chlorophyll molecules is the isocyclic ring. This ring i s formed by the action of the enzyme Mg-protoporphyrin IX monomethyl ester (oxidative) cyclase, which catalyzes a complex reaction in which Mg-protoporphyrin IX monomethyl ester i s converted to divinyl protochlorophyllide (also called Mg-2,4-divinylpheoporphyrin as), with the participation of NADPH and O...

Chloroplasts are descendents of a cyanobacterial endosymbiont, but many chloroplast protein genes of endosymbiont origin are encoded by the nucleus. The chloroplast-cyanobacteria relationship is a typical target of orthogenomics, an analytical method that focuses on the relationship of orthologous genes. Here, we present results of a pilot study of functional orthogenomics, combining bioinforma...

Water oxidation by photosystem (PS) II in oxygenic photosynthetic organisms is a major source of energy on the earth, leading to the production of a stable reductant. Mechanisms generating a high oxidation potential for water oxidation have been a major focus of photosynthesis research. This potential has not been estimated directly but has been measured by the redox potential of the primary el...

The cyanobacterial phycobilisome is a large protein complex located on the photosynthetic membrane. It harvests light energy and transfers it to chlorophyll for use in photosynthesis. Phycobilisome assembly mutants in the unicellular cyanobacterium Synechocystis sp. strain 6701 have been characterized. One such mutant, UV16, contains a defect in the assembly of the biliprotein phycocyanin. We r...

We compared the relative importance of dietary factors versus de novo synthesis in determining the polyunsaturated fatty acid (PUFA) composition of the heterotrophic nanoflagellate Paraphysomonas sp. The flagellate was fed with different mutants of the picocyanobacterial strain Synechocystis PCC6803, which differ in their capability to synthesize specific PUFAs. The desA, desB, and desD genes o...