Simultaneous Inactivation of Sigma Factors B and D Interferes with Light Acclimation of the Cyanobacterium Synechocystis sp. Strain PCC 6803
- 15 June 2009
- journal article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 191 (12), 3992-4001
- https://doi.org/10.1128/jb.00132-09
Abstract
In cyanobacteria, gene expression is regulated mainly at the level of transcription initiation, which is mediated by the RNA polymerase holoenzyme. The RNA polymerase core is catalytically active, while the σ factor recognizes promoter sequences. Group 2 σ factors are similar to the principal σ factor but are nonessential. Group 2 σ factors SigB and SigD are structurally the most similar σ factors in Synechocystis sp. strain PCC 6803. Under standard growth conditions, simultaneous inactivation of sigB and sigD genes did not affect the growth, but the photosynthesis and growth of the Δ sigBD strain were slower than in the control strain at double light intensity. Light-saturated electron transfer rates and the fluorescence and thermoluminescence measurements showed that photosynthetic light reactions are fully functional in the Δ sigBD strain, but absorption and 77 K emission spectra measurements suggest that the light-harvesting system of the Δ sigBD strain does not acclimate normally to higher light intensity. Furthermore, the Δ sigBD strain is more sensitive to photoinhibition under bright light because impaired upregulation of psbA genes leads to insufficient PSII repair.Keywords
This publication has 58 references indexed in Scilit:
- Connectivity of Photosystem II Is the Physical Basis of Retrapping in Photosynthetic ThermoluminescenceBiophysical Journal, 2009
- A photoactive carotenoid protein acting as light intensity sensorProceedings of the National Academy of Sciences of the United States of America, 2008
- Stringent promoter recognition and autoregulation by the group 3 σ-factor SigF in the cyanobacterium Synechocystis sp. strain PCC 6803Nucleic Acids Research, 2008
- Characterization of Single and Double Inactivation Strains Reveals New Physiological Roles for Group 2 σ Factors in the Cyanobacterium Synechocystis sp. PCC 6803Plant Physiology, 2008
- Role of Sigma Factors in Controlling Global Gene Expression in Light/Dark Transitions in the Cyanobacterium Synechocystis sp. Strain PCC 6803Journal of Bacteriology, 2007
- Coordinated High-Light Response of Genes Encoding Subunits of Photosystem I Is Achieved by AT-Rich Upstream Sequences in the Cyanobacterium Synechocystis sp. Strain PCC 6803Journal of Bacteriology, 2007
- Specific Binding of D1 Protein Degradation Products to the psbAI Promoter in Synechococcus sp. Strain PCC 7942Journal of Bacteriology, 2007
- Supramolecular Organization and Dual Function of the IsiA Chlorophyll-Binding Protein in CyanobacteriaBiochemistry, 2004
- Genome-Wide Dynamic Transcriptional Profiling of the Light-to-Dark Transition inSynechocystissp. Strain PCC 6803Journal of Bacteriology, 2002
- Sequence Analysis of the Genome of the Unicellular Cyanobacterium Synechocystis sp. Strain PCC6803. II. Sequence Determination of the Entire Genome and Assignment of Potential Protein-coding RegionsDNA Research, 1996