Stark effect in wild-type and heterodimer-containing reaction centers from Rhodobacter capsulatus

Biochemistry ◽  
1990 ◽  
Vol 29 (4) ◽  
pp. 899-907 ◽  
Author(s):  
Theodore J. DiMagno ◽  
Edward J. Bylina ◽  
Alexander Angerhofer ◽  
Douglas C. Youvan ◽  
James R. Norris
Keyword(s):  
Stark Effect ◽  
Rhodobacter Capsulatus ◽  
Reaction Centers ◽  
Wild Type

Temperature-independent electron transfer in Rhodobacter capsulatus wild-type and HisM200 .fwdarw. Leu photosynthetic reaction centers

1991 ◽  
Vol 95 (8) ◽  
pp. 3379-3383 ◽  
Author(s):  
Lynda M. McDowell ◽  
Christine Kirmaier ◽  
Dewey Holten
Keyword(s):  
Electron Transfer ◽  
Rhodobacter Capsulatus ◽  
Reaction Centers ◽  
Photosynthetic Reaction Centers ◽  
Wild Type

Detergent effects on primary charge separation in wild-type and mutant Rhodobacter capsulatus reaction centers

2003 ◽  
Vol 294 (3) ◽  
pp. 305-318 ◽  
Author(s):  
Christine Kirmaier ◽  
Philip D. Laible ◽  
Eve Hindin ◽  
Deborah K. Hanson ◽  
Dewey Holten
Keyword(s):  
Charge Separation ◽  
Rhodobacter Capsulatus ◽  
Reaction Centers ◽  
Wild Type ◽  
Primary Charge Separation

Control of dimethylsulfoxide reductase expression in Rhodobacter capsulatus: the role of carbon metabolites and the response regulators DorR and RegA

Microbiology ◽  
2002 ◽  
Vol 148 (2) ◽  
pp. 605-614 ◽  
Author(s):  
Ulrike Kappler ◽  
Wilhelmina M Huston ◽  
Alastair G McEwan
Keyword(s):  
Gene Expression ◽  
Carbon Source ◽  
Rhodobacter Capsulatus ◽  
Response Regulator ◽  
Reductase Activity ◽  
Negative Regulator ◽  
Wild Type ◽  
Dmso Reductase ◽  
Dimethylsulfoxide Reductase ◽  
Operon Expression

Regulation of the expression of dimethylsulfoxide (DMSO) reductase was investigated in the purple phototrophic bacterium Rhodobacter capsulatus. Under phototrophic, anaerobic conditions with malate as carbon source, DMSO caused an approximately 150-fold induction of DMSO reductase activity. The response regulator DorR was required for DMSO-dependent induction and also appeared to slightly repress DMSO reductase expression in the absence of substrate. Likewise, when pyruvate replaced malate as carbon source there was an induction of DMSO reductase activity in cells grown at low light intensity (16 W m−2) and again this induction was dependent on DorR. The level of DMSO reductase activity in aerobically grown cells was elevated when pyruvate replaced malate as carbon source. One possible explanation for this is that acetyl phosphate, produced from pyruvate, may activate expression of DMSO reductase by direct phosphorylation of DorR, leading to low levels of induction of dor gene expression in the absence of DMSO. A mutant lacking the global response regulator of photosynthesis gene expression, RegA, exhibited high levels of DMSO reductase in the absence of DMSO, when grown phototrophically with malate as carbon source. This suggests that phosphorylated RegA acts as a repressor of dor operon expression under these conditions. It has been proposed elsewhere that RegA-dependent expression is negatively regulated by the cytochrome cbb 3 oxidase. A cco mutant lacking cytochrome cbb 3 exhibited significantly higher levels of Φ[dorA::lacZ] activity in the presence of DMSO compared to wild-type cells and this is consistent with the above model. Pyruvate restored DMSO reductase expression in the regA mutant to the same pattern as found in wild-type cells. These data suggest that R. capsulatus contains a regulator of DMSO respiration that is distinct from DorR and RegA, is activated in the presence of pyruvate, and acts as a negative regulator of DMSO reductase expression.

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