Idium (B) in cell populations of the indicated genotypes. The red vertical bar represents the median fluorescence of wild-type cells (WT); the percentage of cells with a lower (V1-L; V3-L) or higher fluorescence (V1-R; V3-R) is indicated for each strain. The mean/median values are indicated below each graph. The distributions of rhodamine 123 (and DYm) 25033180 as well as ethidium (superoxide) are shifted towards lower values, below the median of WT-cells, in all mutant strains. (TIFF)Figure S3 Deletion or mutation of mitochondrial ATP6 is associated to alterations of mitochondrial distribution and morphology. Yeast cells expressing fluorescent proteins targeted to the mitochondrial matrix were grown to the log phase, fixed and analyzed by fluorescence microscopy. Wild-type strains and strains deleted for mitochondrial COX2 display filamentous mitochondria. Strains with deletion or L247R-mutation of mitochondrial ATP6 display clustered mitochondria. Other OXPHOS-deficient strains (atp6-L183R, Datp12, r0) display filamentous and clustered mitochondria. (TIFF)AcknowledgmentsWe thank Nathalie Bonnefoy (Gif-sur-Yvette ?France), Agnes Delahodde ` (Orsay – France), Koji Okamoto (Okazaki ?Japan), Andreas Reichert (Frankfurt-am-Main – Germany), Benedikt Westermann (Bayreuth Germany) and Michael Zick (Munich ?Germany) for providing valuable reagents. We are grateful to Anne Devin, Stephen Manon and Claire Lordan for valuable advice and experimental assistance.Author ContributionsConceived and designed the experiments: CS SDC JPdR MR. Performed the experiments: CS SDC BS CD AML. Analyzed the data: CS SDC JPdR MR. Wrote the paper: MR.
LEPA is one of the most conserved proteins, and it has the unexpected ability to back-translocate tRNAs on the ribosome [1]. LEPA homologs are highly conserved in terms of both their structure and their amino acid sequence, and they are found in bacteria, mitochondria and chloroplasts, but not in archaea or in the cytoplasm of eukaryotes [1]. Based on the domain definition of EF-G, LEPA can be divided into five domains, four out of the five EF-G domains , II, III, and V re present in LEPA. Domain IV and the G9 subdomain of domain I of EF-G are absent. LEPA has a special C-terminal domain called CTD with an unusual fold which might interact with tRNA or 23S rRNA [2]. Although the overall structure of LEPA has been described in great detail, the physiological functions involved in translation have not yet been resolved. In E. coli, LEPA is located upstream of the LEP gene, which encodes nonspecific signal peptidase I [3]. Deletion of LEPA does not cause any apparent phenotype under optimal growth conditions [4,5]. These observations are difficult to reconcile with the ubiquity of LEPA and its extreme conservation. Other results have demonstrated that, although E. coli LEPAdefective cells grown in rich medium have no phenotype [4], under several stress conditions, including high salt, low pH, and low temperature, 16574785 the LEPA mutant is overgrown by wild-type bacterial cells [6]. In bacteria, DLEPA strains have been shown to be hypersensitive to potassium tellurite and MedChemExpress 301353-96-8 penicillin [7] and to enhance the production of the calcium-dependent antibiotic in Streptomyces 548-04-9 bacteria [8]. Recent studies suggested that LEPA may react with both the PRE and POST ribosome complexes, leading to the formation of an intermediate complex that effectively sequesters a catalytically active ribosome, resulting in a transientinhibition of elongation that pr.Idium (B) in cell populations of the indicated genotypes. The red vertical bar represents the median fluorescence of wild-type cells (WT); the percentage of cells with a lower (V1-L; V3-L) or higher fluorescence (V1-R; V3-R) is indicated for each strain. The mean/median values are indicated below each graph. The distributions of rhodamine 123 (and DYm) 25033180 as well as ethidium (superoxide) are shifted towards lower values, below the median of WT-cells, in all mutant strains. (TIFF)Figure S3 Deletion or mutation of mitochondrial ATP6 is associated to alterations of mitochondrial distribution and morphology. Yeast cells expressing fluorescent proteins targeted to the mitochondrial matrix were grown to the log phase, fixed and analyzed by fluorescence microscopy. Wild-type strains and strains deleted for mitochondrial COX2 display filamentous mitochondria. Strains with deletion or L247R-mutation of mitochondrial ATP6 display clustered mitochondria. Other OXPHOS-deficient strains (atp6-L183R, Datp12, r0) display filamentous and clustered mitochondria. (TIFF)AcknowledgmentsWe thank Nathalie Bonnefoy (Gif-sur-Yvette ?France), Agnes Delahodde ` (Orsay – France), Koji Okamoto (Okazaki ?Japan), Andreas Reichert (Frankfurt-am-Main – Germany), Benedikt Westermann (Bayreuth Germany) and Michael Zick (Munich ?Germany) for providing valuable reagents. We are grateful to Anne Devin, Stephen Manon and Claire Lordan for valuable advice and experimental assistance.Author ContributionsConceived and designed the experiments: CS SDC JPdR MR. Performed the experiments: CS SDC BS CD AML. Analyzed the data: CS SDC JPdR MR. Wrote the paper: MR.
LEPA is one of the most conserved proteins, and it has the unexpected ability to back-translocate tRNAs on the ribosome [1]. LEPA homologs are highly conserved in terms of both their structure and their amino acid sequence, and they are found in bacteria, mitochondria and chloroplasts, but not in archaea or in the cytoplasm of eukaryotes [1]. Based on the domain definition of EF-G, LEPA can be divided into five domains, four out of the five EF-G domains , II, III, and V re present in LEPA. Domain IV and the G9 subdomain of domain I of EF-G are absent. LEPA has a special C-terminal domain called CTD with an unusual fold which might interact with tRNA or 23S rRNA [2]. Although the overall structure of LEPA has been described in great detail, the physiological functions involved in translation have not yet been resolved. In E. coli, LEPA is located upstream of the LEP gene, which encodes nonspecific signal peptidase I [3]. Deletion of LEPA does not cause any apparent phenotype under optimal growth conditions [4,5]. These observations are difficult to reconcile with the ubiquity of LEPA and its extreme conservation. Other results have demonstrated that, although E. coli LEPAdefective cells grown in rich medium have no phenotype [4], under several stress conditions, including high salt, low pH, and low temperature, 16574785 the LEPA mutant is overgrown by wild-type bacterial cells [6]. In bacteria, DLEPA strains have been shown to be hypersensitive to potassium tellurite and penicillin [7] and to enhance the production of the calcium-dependent antibiotic in Streptomyces bacteria [8]. Recent studies suggested that LEPA may react with both the PRE and POST ribosome complexes, leading to the formation of an intermediate complex that effectively sequesters a catalytically active ribosome, resulting in a transientinhibition of elongation that pr.