biostudies-literatureUnknown193(1)Pollari MAcclimation of cyanobacteria to environmental changes includes major changes in the gene expression patterns partly orchestrated by the replacement of a particular σ subunit with another in the RNA polymerase holoenzyme. The cyanobacterium Synechocystis sp. strain PCC 6803 encodes nine σ factors, all belonging to the σ(70) family. Cyanobacteria typically encode many group 2 σ factors that closely resemble the principal σ factor. We inactivated three out of the four group 2 σ factors of Synechocystis simultaneously in all possible combinations and found that all triple inactivation strains grow well under standard conditions. Unlike the other strains, the ΔsigBCD strain, which contains SigE as the only functional group 2 σ factor, did not grow faster under mixotrophic than under autotrophicJournal of bacteriology265-73https://www.ebi.ac.uk/biostudies/studies/S-EPMC3019964biostudies-literatureEffects of deficiency and overdose of group 2 sigma factors in triple inactivation strains of Synechocystis sp. strain PCC 6803.PMC3019964Virjamo VTyystjarvi ETyystjarvi TPollari MRantamaki SHuokko TKarlund-Marttila AfalseEffects of deficiency and overdose of group 2 sigma factors in triple inactivation strains of Synechocystis sp. strain PCC 6803.Acclimation of cyanobacteria to environmental changes includes major changes in the gene expression patterns partly orchestrated by the replacement of a particular σ subunit with another in the RNA polymerase holoenzyme. The cyanobacterium Synechocystis sp. strain PCC 6803 encodes nine σ factors, all belonging to the σ(70) family. Cyanobacteria typically encode many group 2 σ factors that closely resemble the principal σ factor. We inactivated three out of the four group 2 σ factors of Synechocystis simultaneously in all possible combinations and found that all triple inactivation strains grow well under standard conditions. Unlike the other strains, the ΔsigBCD strain, which contains SigE as the only functional group 2 σ factor, did not grow faster under mixotrophic than under autotrophic2011-01-01T00:00:00Z2011 Jan2025-04-22T21:00:18.106Z2019-03-27T00:38:03ZS-EPMC30199642097191610.1128/JB.01045-1010.1128/jb.01045-10