PcrX, an sRNA derived from the 3′- UTR of the Rhodobacter sphaeroides puf operon modulates expression of puf genes encoding proteins of the bacterial photosynthetic apparatus

2018 ◽  
Vol 110 (3) ◽  
pp. 325-334 ◽  
Author(s):  
Katrin M.H. Eisenhardt ◽  
Carina M. Reuscher ◽  
Gabriele Klug
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Photosynthetic Apparatus ◽  
Puf Operon ◽  
Puf Genes ◽  
Genes Encoding

scholarly journals Hierarchical Regulation of Photosynthesis Gene Expression by the Oxygen-Responsive PrrBA and AppA-PpsR Systems of Rhodobacter sphaeroides

2008 ◽  
Vol 190 (24) ◽  
pp. 8106-8114 ◽  
Author(s):  
Larissa Gomelsky ◽  
Oleg V. Moskvin ◽  
Rachel A. Stenzel ◽  
Denise F. Jones ◽  
Timothy J. Donohue ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rhodobacter Sphaeroides ◽  
Response Regulator ◽  
Photosynthetic Apparatus ◽  
Regulatory System ◽  
Structural Proteins ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Photosynthetic Complexes ◽  
Photosynthesis Gene

ABSTRACT In the facultatively phototrophic proteobacterium Rhodobacter sphaeroides, formation of the photosynthetic apparatus is oxygen dependent. When oxygen tension decreases, the response regulator PrrA of the global two-component PrrBA system is believed to directly activate transcription of the puf, puh, and puc operons, encoding structural proteins of the photosynthetic complexes, and to indirectly upregulate the photopigment biosynthesis genes bch and crt. Decreased oxygen also results in inactivation of the photosynthesis-specific repressor PpsR, bringing about derepression of the puc, bch, and crt operons. We uncovered a hierarchical relationship between these two regulatory systems, earlier thought to function independently. We also more accurately assessed the spectrum of gene targets of the PrrBA system. First, expression of the appA gene, encoding the PpsR antirepressor, is PrrA dependent, which establishes one level of hierarchical dominance of the PrrBA system over AppA-PpsR. Second, restoration of the appA transcript to the wild-type level is insufficient for rescuing phototrophic growth impairment of the prrA mutant, whereas inactivation of ppsR is sufficient. This suggests that in addition to controlling appA transcription, PrrA affects the activity of the AppA-PpsR system via an as yet unidentified mechanism(s). Third, PrrA directly activates several bch and crt genes, traditionally considered to be the PpsR targets. Therefore, in R. sphaeroides, the global PrrBA system regulates photosynthesis gene expression (i) by rigorous control over the photosynthesis-specific AppA-PpsR regulatory system and (ii) by extensive direct transcription activation of genes encoding structural proteins of photosynthetic complexes as well as genes encoding photopigment biosynthesis enzymes.

scholarly journals Effect of oxygen on levels of mRNA coding for reaction-centre and light-harvesting polypeptides of Rhodobacter sphaeroides

1987 ◽  
Vol 247 (2) ◽  
pp. 489-492 ◽  
Author(s):  
C N Hunter ◽  
M K Ashby ◽  
S A Coomber
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Light Harvesting ◽  
Photosynthetic Apparatus ◽  
Maximum Level ◽  
Reaction Centre ◽  
Puf Operon ◽  
Effect Of Oxygen

The relative levels of mRNA for the reaction-centre L and M subunits, B875 (LH1) alpha and beta polypeptides and B800-850 (LH2) alpha and beta polypeptides, have been measured during pigment induction of Rhodobacter sphaeroides. Over the 6 h of the experiment, bacteriochlorophyll levels increased by at least 100-fold. No transcripts for photosynthetic components were detectable at the start of induction; after 2 h the levels of transcripts from the puf operon (encoding reaction-centre and B875 subunits) had reached the maximum; these transcripts were 2.7 and 0.5 kb respectively. The transcript for the puc operon (B800-850 complex) was estimated to be 0.55 kb and reached a maximum level after 6 h. These results are consistent with the proposal that, during the assembly of the photosynthetic apparatus, the synthesis of B875 reaction-centre aggregates precedes that of the major antenna, B800-850.

scholarly journals Origin of the mRNA stoichiometry of the puf operon in Rhodobacter sphaeroides.

1986 ◽  
Vol 261 (22) ◽  
pp. 10366-10374 ◽  
Author(s):  
Y S Zhu ◽  
P J Kiley ◽  
T J Donohue ◽  
S Kaplan
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Puf Operon

scholarly journals Interplay between formation of photosynthetic complexes and expression of genes for iron–sulfur cluster assembly in Rhodobacter sphaeroides?

2020 ◽  
Vol 147 (1) ◽  
pp. 39-48
Author(s):  
Xin Nie ◽  
Andreas Jäger ◽  
Janek Börner ◽  
Gabriele Klug
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Cluster Formation ◽  
Rna Stability ◽  
Photosynthetic Apparatus ◽  
Growth Conditions ◽  
Cluster Assembly ◽  
Iron Sulfur Cluster ◽  
Expression Of Genes ◽  
Photosynthetic Complexes ◽  
Photosynthesis Genes

AbstractFormation of photosynthetic complexes leads to a higher demand for Fe–S clusters. We hypothesized that in the facultative phototrophic alpha-proteobacterium Rhodobacter sphaeroides expression of the isc-suf operon for Fe–S cluster formation may be increased under conditions that promote formation of photosynthetic complexes and that, vice versa, lack of the IscR regulator may also affect photosynthesis gene expression. To test this hypothesis, we monitored the activities of the isc-suf sense and anti-sense promoters under different growth conditions and in mutants which are impaired in formation of photosynthetic complexes. We also tested expression of photosynthesis genes in a mutant lacking the IscR regulator. Our results are not in agreement with a co-regulation of the Isc-Suf system and the photosynthetic apparatus at level of transcription. We provide evidence that, coordination of the systems occurs at post-transcriptional levels. Increased levels of isc-suf mRNAs under conditions promoting formation of photosynthetic complexes are due to higher RNA stability.

scholarly journals Role of the Global Transcriptional Regulator PrrA in Rhodobacter sphaeroides 2.4.1: Combined Transcriptome and Proteome Analysis

2008 ◽  
Vol 190 (14) ◽  
pp. 4831-4848 ◽  
Author(s):  
Jesus M. Eraso ◽  
Jung Hyeob Roh ◽  
Xiaohua Zeng ◽  
Stephen J. Callister ◽  
Mary S. Lipton ◽  
...  
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Regulatory System ◽  
Proteome Analysis ◽  
Orthologous Group ◽  
Transcriptional Level ◽  
Chromatographic Study ◽  
Metabolic Genes ◽  
Genes Encoding ◽  
Parameter Values

ABSTRACTThe PrrBA two-component regulatory system is a major global regulator inRhodobacter sphaeroides2.4.1. Here we have compared the transcriptome and proteome profiles of the wild-type (WT) and mutant PrrA2 cells grown anaerobically in the dark with dimethyl sulfoxide as an electron acceptor. Approximately 25% of the genes present in the PrrA2 genome are regulated by PrrA at the transcriptional level, either directly or indirectly, by twofold or more relative to the WT. The genes affected are widespread throughout all COG (cluster of orthologous group) functional categories, with previously unsuspected “metabolic” genes affected in PrrA2 cells. PrrA was found to act as both an activator and a repressor of transcription, with more genes being repressed in the presence of PrrA (9:5 ratio). An analysis of the genes encoding the 1,536 peptides detected through our chromatographic study, which corresponds to 36% coverage of the genome, revealed that approximately 20% of the genes encoding these proteins were positively regulated, whereas approximately 32% were negatively regulated by PrrA, which is in excellent agreement with the percentages obtained for the whole-genome transcriptome profile. In addition, comparison of the transcriptome and proteome mean parameter values for WT and PrrA2 cells showed good qualitative agreement, indicating that transcript regulation paralleled the corresponding protein abundance, although not one for one. The microarray analysis was validated by direct mRNA measurement of randomly selected genes that were both positively and negatively regulated.lacZtranscriptional andkantranslational fusions enabled us to map putative PrrA binding sites and revealed potential gene targets for indirect regulation by PrrA.

scholarly journals Nitrite and Nitrous Oxide Reductase Regulation by Nitrogen Oxides in Rhodobacter sphaeroides f. sp.denitrificans IL106

1999 ◽  
Vol 181 (19) ◽  
pp. 6028-6032 ◽  
Author(s):  
Monique Sabaty ◽  
Carole Schwintner ◽  
Sandrine Cahors ◽  
Pierre Richaud ◽  
Andre Verméglio
Keyword(s):  
Nitrous Oxide ◽  
Nitrate Reductase ◽  
Rhodobacter Sphaeroides ◽  
Type Strain ◽  
Biochemical Analysis ◽  
Wild Type Strain ◽  
Nitrous Oxide Reductase ◽  
Wild Type ◽  
Genes Encoding ◽  
Membrane Bound

ABSTRACT We have cloned the nap locus encoding the periplasmic nitrate reductase in Rhodobacter sphaeroides f. sp.denitrificans IL106. A mutant with this enzyme deleted is unable to grow under denitrifying conditions. Biochemical analysis of this mutant shows that in contrast to the wild-type strain, the level of synthesis of the nitrite and N2O reductases is not increased by the addition of nitrate. Growth under denitrifying conditions and induction of N oxide reductase synthesis are both restored by the presence of a plasmid containing the genes encoding the nitrate reductase. This demonstrates that R. sphaeroides f. sp. denitrificans IL106 does not possess an efficient membrane-bound nitrate reductase and that nitrate is not the direct inducer for the nitrite and N2O reductases in this species. In contrast, we show that nitrite induces the synthesis of the nitrate reductase.

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