The role of dor gene products in controlling the P2 promoter of the cytochrome c 2 gene, cycA, in Rhodobacter sphaeroides

Tavano, Christine L.; Comolli, James C.; Donohue, Timothy J.

doi:10.1099/mic.0.26971-0

Cited by 4 publications

(2 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is not surprising to find that anoxygenic phototrophs are able to use a variety of pathways to recycle excess reducing power when one considers the myriad of electron donors and acceptors that these organisms are likely to encounter in nature. An additional link in the cycle of reducing power is seen by the ability of added electron acceptors to alter photosynthetic gene expression, and development of the photosynthetic apparatus [35,[44][45][46].…”

Section: Control Of Photosynthetic Membrane Developmentmentioning

confidence: 99%

Development of the bacterial photosynthetic apparatus

Tavano

Donohue

2006

Current Opinion in Microbiology

View full text Add to dashboard Cite

Anoxygenic photosynthetic bacteria have provided us with crucial insights into the process of solar energy capture, pathways of metabolic and societal importance, specialized differentiation of membrane domains, function or assembly of bioenergetic enzymes, and into the genetic control of these and other activities. Recent insights into the organization of this bioenergetic membrane system, the genetic control of this specialized domain of the inner membrane and the process by which potentially photosynthetic and non-photosynthetic cells protect themselves from an important class of reactive oxygen species will provide an unparalleled understanding of solar energy capture and facilitate the design of solar-powered microbial biorefineries.

show abstract

Section: Control Of Photosynthetic Membrane Developmentmentioning

confidence: 99%

Development of the bacterial photosynthetic apparatus

Tavano

Donohue

2006

Current Opinion in Microbiology

View full text Add to dashboard Cite

show abstract

“…Primers (100 pmol) specific to RSP4157 (5Ј-GGTT CTTCGCTTCGCTTCGCATTG-3Ј), pucB (5Ј-GTTCAGATCGTCAGTCACT GTGTCGTC-3Ј), or coxII (5Ј-AGGTCGTGGAATGTCTCATG-3Ј) were radiolabeled with [␥-32 P]ATP (35). ␣-32 P-labeled primers (6.7 pmol) were annealed to 10 g RNA in 50 mM Tris-Cl (pH 8.3)-60 mM NaCl-10 mM DTT by heating to 95°C for 2 min and slowly cooled to 40°C.…”

Section: Methodsmentioning

confidence: 99%

Identification of Genes Required for Recycling Reducing Power during Photosynthetic Growth

2005

Self Cite

View full text Add to dashboard Cite

Photosynthetic organisms have the unique ability to transform light energy into reducing power. We study the requirements for photosynthesis in the ␣-proteobacterium Rhodobacter sphaeroides. Global gene expression analysis found that ϳ50 uncharacterized genes were regulated by changes in light intensity and O 2 tension, similar to the expression of genes known to be required for photosynthetic growth of this bacterium. These uncharacterized genes included RSP4157 to -4159, which appeared to be cotranscribed and map to plasmid P004. A mutant containing a polar insertion in RSP4157, CT01, was able to grow via photosynthesis under autotrophic conditions using H 2 as an electron donor and CO 2 as a carbon source. However, CT01 was unable to grow photoheterotrophically in a succinate-based medium unless compounds that could be used to recycle reducing power (the external electron acceptor dimethyl sulfoxide (DMSO) or CO 2 ) were provided. This suggests that the insertion in RSP4157 caused a defect in recycling reducing power during photosynthetic growth when a fixed carbon source was present. CT01 had decreased levels of RNA for genes encoding putative glycolate degradation functions. We found that exogenous glycolate also rescued photoheterotrophic growth of CT01, leading us to propose that CO 2 produced from glycolate metabolism can be used by the Calvin cycle to recycle reducing power generated in the photosynthetic apparatus. The ability of glycolate, CO 2 , or DMSO to support photoheterotrophic growth of CT01 suggests that one or more products of RSP4157 to -4159 serve a previously unknown role in recycling reducing power under photosynthetic conditions. Life on earth is dependent upon photosynthesis, either directly using energy from sunlight or indirectly through the use of organic compounds produced by photosynthetic organisms. Due to the importance of photosynthesis, much research has been devoted to understanding this process in plants, algae, and photosynthetic bacteria. The defining feature of all photosynthetic organisms is their ability to use light energy to generate reducing power, which is used to support the synthesis of ATP, the assimilation of CO 2 , or the synthesis of other compounds. We are studying the requirements for photosynthesis in the ␣-proteobacterium Rhodobacter sphaeroides, a facultative phototroph that also can produce energy by aerobic or anaerobic respiratory pathways.Since the continual flow of electrons through electron carriers is critical to energy production, cells have evolved strategies to maintain necessary electron flow by recycling or disposing of excess reducing power. For example, fermentative pathways use organic compounds as electron acceptors, and electron transport to O 2 allows the aerobic respiratory chain to produce energy. When O 2 is absent, anaerobic respiratory pathways reduce alternate electron acceptors like dimethyl sulfoxide (DMSO) to dispose of excess reducing power (18). Photosynthetic growth also requires a strategy for recycling reducing power, but di...

show abstract