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Title: The omega subunit of the RNA polymerase core directs transcription efficiency in cyanobacteria      
dateReleased:
01-30-2014
description:
The catalytic core of the RNA polymerase of most eubacteria is composed of two α subunits and β, β’ and ω subunits. In Escherichia coli, the ω subunit (encoded by the rpoZ gene) has been suggested to assist β’ during RNA polymerase core assembly. The function of the ω subunit is particularly interesting in cyanobacteria because the cyanobacterial β’ is split to N-terminal γ and C-terminal β’ subunits. The ∆rpoZ strain of the cyanobacterium Synechocystis sp. PCC 6803 grew well in standard conditions although the mutant cells showed low light-saturated photosynthetic activity, low Rubisco content and accumulated high quantities of protective carotenoids and α-tocopherol. The ∆rpoZ strain contained 15% less of the primary σ factor, SigA, than the control strain, and recruitment of SigA to the RNA polymerase core was inefficient in ∆rpoZ. Thus, a cyanobacterial RNA polymerase holoenzyme lacking the ω subunit contains less frequently the primary σ factor. A DNA microarray analysis revealed that this leads to specific down-regulation of highly expressed genes, like genes encoding subunits for Rubisco, ATP synthase, NADH-dehydrogenase and carbon concentrating mechanisms. On the contrary, many genes showing only low or moderate expression in the control strain were up-regulated in ∆rpoZ. A conserved -10 region was detected in promoters showing up or down-regulation in ∆rpoZ, but -35 regions of down-regulated genes completely differed from -35 regions of up-regulated genes. Cells from cyanobacteria Synechocystis sp. PCC 6803 named as control strain (CS) and RNA polymerase omega subunit inactivation strain, ΔrpoZ, were harvested (A730=1, 40 mL) directly from standard growth conditions (continuous illumination at the PPFD of 40 µmol m-2s-1, 32°C, ambient CO2). From three to four independent experiments were performed at each conditions.
privacy:
not applicable
aggregation:
instance of dataset
ID:
E-GEOD-51647
refinement:
raw
alternateIdentifiers:
51647
keywords:
functional genomics
dateModified:
02-18-2014
availability:
available
types:
gene expression
name:
Synechocystis sp. PCC 6803
ID:
A-GEOD-17595
name:
Agilent-016989 Synechocystis array [ORF version]
accessURL: https://www.ebi.ac.uk/arrayexpress/files/E-GEOD-51647/E-GEOD-51647.raw.1.zip
storedIn:
ArrayExpress
qualifier:
gzip compressed
format:
TXT
accessType:
download
authentication:
none
authorization:
none
accessURL: https://www.ebi.ac.uk/arrayexpress/files/E-GEOD-51647/E-GEOD-51647.processed.1.zip
storedIn:
ArrayExpress
qualifier:
gzip compressed
format:
TXT
accessType:
download
authentication:
none
authorization:
none
accessURL: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE51647
storedIn:
Gene Expression Omnibus
qualifier:
not compressed
format:
HTML
accessType:
landing page
primary:
true
authentication:
none
authorization:
none
abbreviation:
EBI
homePage: http://www.ebi.ac.uk/
ID:
SCR:004727
name:
European Bioinformatics Institute
homePage: https://www.ebi.ac.uk/arrayexpress/
ID:
SCR:002964
name:
ArrayExpress

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