Schlunzen, F. et al. Reprod. However, macrolides also expose people to the risk of adverse events. We also detect additional density that would be consistent with a water molecule (W2) forming a bridging interaction between the side chain of TEL and the O6 of G880 (748) of the 25S rRNA (Fig. Tetracenomycin X inhibits translation by binding within the ribosomal exit tunnel. USA 114, 1367313678 (2017). Microbiol 11, 414421 (2008). The prospect of such an approach hinges, however, on the macrolides retaining their context-selectivity and protein-selectivity of inhibition of protein synthesis in a eukaryotic cell. Thus, in eukaryotes, just like in bacteria, TEL appears to act as an inhibitor of peptide bond formation between specific donor and acceptor substrates rather than as a discriminating gateway for the growing protein chain. 4b, lower left quadrant). TEL, SOL, cethromycin (CET), and RU3004, all of which carry the C3-keto group instead of cladinose, had only a small effect on expression of Zeo1 (Fig. Adv. f, g Bottom panels: Metagene analyses of ribosome density around the +X+ (f) and PDX (g) arrest motifs in TEL-treated (orange plots) and untreated (black plots) cells. INTRODUCTION. Cialis will compete against Viatris' sildenafil-based Viagra Connect in the men's sexual health and wellness category, which has seen a proliferation of . 45, 95739582 (2017). The graphs represent results of two independent experiments with individual data points indicated. Almutairi, M. M. et al. EMBnet J. Davis, A. R., Gohara, D. W. & Yap, M. N. Sequence selectivity of macrolide-induced translational attenuation. Arrowheads and arrows/asterisk represent the bands corresponding to the full-length and truncated products, respectively. Biol. A macrolide antibiotic, TEL or SOL, was added to different final concentrations, which were ranging from 15g/mL (0.08x MIC) to 6mg/mL (32x MIC) for TEL and from 1g/mL (0.02x MIC) to 1mg/mL (20x MIC) for SOL. For example, upregulation of expression of ribosomal proteins uL6 (gene RPL9), eL15 (RPL15), and eL39 (RPL39) is associated with increased tumor growth and metastasis in some cancers65,66,67. & Liebman, S. W. Mutations in eukaryotic 18S ribosomal RNA affect translational fidelity and resistance to aminoglycoside antibiotics. The position of the cDNA bands corresponding to the nucleotide residues A2400 and A2401 are indicated by the arrows. Binding of macrolide antibiotics leads to ribosomal selection against specific substrates based on their charge and size. Starosta, A. L. et al. Resistance to so many treatment options, including penicillins, sulphonamides, tetracyclines, quinolones and macrolides (including azithromycin), as well as so-called last line options like cephalosporins, make N. gonorrhoeae a multidrug resistant organism. 6a, b). Nucleic Acids Res. Such protection, caused by a direct interaction of the drugs C5 side chain with this nucleotide, which has been noted previously in archaeal and bacterial ribosomes51,52, is indicative of a similar binding mode of these drugs in the eukaryotic ribosome. Macrolides. Mutating in silico A2400 back to G in our structure or aligning the TEL-60S complex with the vacant wt yeast 80S ribosomes46, suggests that the N2 position of G2400 would mildly clash with the desosamine sugar of TEL (Supplementary Fig. According to the location of the TEL binding site in the NPET of the yeast ribosome (Fig. Use the Previous and Next buttons to navigate the slides or the slide controller buttons at the end to navigate through each slide. In order to minimize secondary stress-related effects, the exponentially growing G2400A yeast cells were exposed for only a brief time (10min) to a high concentration of TEL (1.5mg/mL equivalent to 8 MIC), that result in ~90% inhibition of protein synthesis (Supplementary Fig. 2b, c, respectively. However, very limited research has been dedicated towards finding molecules, that could curb the production of specific proteins by acting upon the ribosome. Science 367, 14681473 (2020). Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA, Maxim S. Svetlov,Sezen Meydan,Dorota Klepacki,Nora Vzquez-Laslop&Alexander S. Mankin, Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA, Maxim S. Svetlov,Nora Vzquez-Laslop&Alexander S. Mankin, Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA, Postdoctoral Research Associate Training Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD, USA, Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland, You can also search for this author in The image was generated using PyMOL (Schrdinger, LLC). Sci. Upon reaching an absorbance of A600~0.7, cells were harvested by fast filtration, flash-frozen in liquid nitrogen and lysed using Mixer Mill MM400 (Retsch) as described above for ribosome profiling. A. et al. 6c, d). Nature 533, 338345 (2016). The N1 of A2400(A2058) forms a hydrogen bond interaction to the hydroxyl group of the desosamine sugar of TEL and a water molecule (W1) mediates interaction of the desosamines dimethylamine with the N6 of A2400(A2058), as was also observed in bacteria43. In mutant (but not wt) yeast ribosomes, SOL and TEL protected the two equivalent rRNA residues, A2400 and A2401, from DMS modification (Fig. To understand the precise binding mode of the extended macrolides in the yeast ribosome, we determined the cryo-EM structure of the mutant G2400A ribosome in complex with TEL with an average resolution of 3.1 (Supplementary Fig. The data are presented as mean values of three independent experiments; error bars show standard deviation. Nucleic Acids Res. 4dh). The yeast ribosome is least susceptible to TEL inhibition when the nascent chain contains Asn at the C-terminus, or when Glu is the incoming amino acid (Supplementary Fig. The smaller product may originate from interruption of GFP translation at the KYKTR109 site, whereas the accumulation of the 22kDa product could be caused by translation arrest at the PDN198 sequence. Due to drug-induced redistribution of ribosomes on mRNAs, such codons are characterized by diminished pause scores in the TEL-treated cells relative to the control (Fig. To further analyze whether binding of SOL and TEL takes place in the NPET of the mutant eukaryotic ribosome, we analyzed drug-rRNA interactions by chemical RNA probing. View or print the patient leaflet as PDF. 72, 185207 (2018). However, TEL and SOL completely abolished the growth of the mutant at concentrations below 200g/ml (TEL) or below 50g/ml (SOL) (Fig. By introducing a single mutation in rRNA, we rendered yeast Saccharomyces cerevisiae cells sensitive to macrolides. Natl Acad. CSH Protoc. The results shown in c, d, f, and g are typical representatives of at least two independent experiments. To address this question in an unbiased way, we analyzed re-distribution of ribosomes on the mRNAs in the TEL-exposed S. cerevisiae cells by ribosome profiling (Ribo-seq)47. ERY and AZI that lacked the alkyl-aryl side chain present in the extended macrolides afforded only marginal protection of these residues (Supplementary Fig. 19.79. Matsuo, Y. et al. 4d). PubMed Central Selective stalling of human translation through small-molecule engagement of the ribosome nascent chain. Elimination of the arrest sequences significantly improved the expression of an otherwise drug-sensitive protein in the presence of the antibiotic. a Structures of representative macrolide antibiotics grouped according to their chemical features: group I, 14-atom macrolactone ring carrying C3 cladinose sugar (framed in red); group II, 14-atom macrolactone ring with C3 keto group (red arrow) and extended alkyl-aryl side chain (gray arrow); group III, 16-member macrolactone with C5 disaccharide chain (framed in red). To remove tRNA and rRNA reads, the files were then aligned to an index of noncoding RNAs with BOWTIE (version 1.1.2)92 using the following parameters: -v 2 -y. We used the engineered mutant to explore the mode of binding of this class of inhibitors to the 80S ribosome, and the effects of macrolides upon translation in the eukaryotic cell. Osterman, I. The map vs. model cross correlation at FSC0.5 was calculated by Phenix (1.19.2-415882) comprehensive cryo-EM validation85 for each map individually using the final molecular model (Supplementary Fig. Natl Acad. The minimal inhibitory concentration (MIC) was determined as the lowest concentration of antibiotic that prevented visible cell growth. Nat. 5c). 180, 519530 (2012). S. cerevisiae NOY891 G2400A mutant cells were grown exponentially at 30C in YPD medium supplemented with Amp. Macrolides are antibiotics that are primarily bacteriostatic; by binding to the 50S subunit of the ribosome, they inhibit bacterial protein synthesis. b Chemically different macrolides readily bind to the yeast G2400A mutant ribosome as revealed by the protection of 25S rRNA residues A2400(2058), A2401(2059) and, in the case of the group III compounds, A2404(2602) from DMS modification. 4e). 4f), as reported previously for ERY43. By submitting a comment you agree to abide by our Terms and Community Guidelines. 3e and 4a, left). 3b and Supplementary Fig. 5ce). (Caister Academic Press, 2015). c pLogo analysis of the sequences of the nine C-terminal residues of the nascent protein (positions 0 to 8) and the A-site amino acid (position +1) at the sites of strongest TEL action. Macrolide antibiotics are known to have antiviral effects. Struct. Genomics 1, 355370 (2004). The lysate was clarified by centrifugation at 20,000g for 5min and the supernatant (~1mL) was desalted by gravity-flow gel-filtration through a 15mL Sephadex G-25 column equilibrated in buffer containing 30mM Hepes-KOH, pH 7.6, 100mM KCl, 2mM DTT, 0.5mM PMSF, and 2mM Mg(OAc)2. We asked whether variation in the structure of the drug bound in the NPET of the yeast ribosome would affect specificity of translation inhibition. Antimicrob. Accumulation of functional Gfp was followed by its fluorescence. Biotechnol. Nucleic Acids Res. Because no accumulation of truncated peptides was observed, these inhibitors possibly block protein synthesis at very early stages of cell-free translation. Int. Nucleic Acids Res. ADS 6). 45, 73267338 (2017). 3bd). They are also effective against chlamydia, Legionella pneumophila and mycoplasma, against which many types of antibiotics, including -lactams, are ineffective. Lintner, N. G. et al. Methods 126, 112129 (2017). CAS They are mostly used for gram-positive cocci organisms and are mainly bacteriostatic due to their inhibition of bacteria growth unless used in high concentrations. Google Scholar. Biol. The Ribo-seq data were highly reproducible between the biological replicates, when gene scores (the relative densities of ribosome footprints mapped to a gene) or pause scores (the relative codon occupancies) were compared (Supplementary Fig. Prior to using the lysate for in vitro transcriptiontranslation assays, the endogenous mRNAs were removed by nuclease treatment. Nat. in press (2020). Particles of combined classes 24 were 3D refined and resolution optimized by CTF refinement through Relion 3.0 resulting in an average resolution of 3.1 (unmasked) and 2.9 (masked) determined using the gold-standard criterion (FSC0.143) (Supplementary Figs. Interestingly, it has been recently shown that the compound tetracenomycin X binds to bacterial and eukaryotic ribosomes in a cavity of the NPET located on the wall opposite to the macrolide binding site and appears to act, at least during bacterial translation, in a sequence-specific manner64. The P-site codons of the +X+ and PDX motifs (highlighted by gray shadowing) are assigned as position 0. Therefore, the PTC-proximal NPET segment emerges as the best target for the inhibitors, whose action depends on the sequence context of the growing polypeptide. Because the bulky macrolide molecule narrows the lumen of the NPET, these antibiotics were initially thought to completely block the passage of any nascent polypeptide and to only allow the synthesis of peptides a few amino acids long17,18. 2a). It is remarkable that in spite of these differences, PF846 and TEL achieve context-specific inhibition of translation by binding to overlapping sites in the NPET. Acta Crystallogr. Ribosomes were ethanol-precipitated and rRNA was extracted. Chem. The broad antibacterial activities of macrolides have led to their widespread use for infections of the gastrointestinal tract, ear, eyes, teeth and skin; for sexually transmitted diseases; and particularly for respiratory infections. Cell 41, 321330 (2011). Nat. 6ce) in spite of the robust binding of these compounds to the G2400A ribosome (Fig. Following incubation, ribosomes were captured using 0.5mg diethyl amino ethyl (DEAE) magnetic beads (BioClone). Ito, K. & Chiba, S. Arrest peptides: cis-acting modulators of translation. At the same time, the distribution of ribosomes within some other ORFs was barely affected by the TEL treatment, suggesting that macrolides affect eukaryotic translation in context-selective and protein-selective manner. Macrolides are a class of antibiotics from a soil-based bacteria called Saccharopolyspora erythraea previously known as S treptomyces bacteria. Macrolide antibiotics allosterically predispose the ribosome for translation arrest. Knockdown of RPL9 expression inhibits colorectal carcinoma growth via the inactivation of Id-1/NF-kappaB signaling axis. Five potential macrolide arrest motifs could be recognized within the Gfp sequence, two of the PDX type (PDH77 and PDN198) and three of the +X+ type, two of them in tandem, KYKTR109, and the single KQK158 (Fig. Nat. Cell 151, 508520 (2012). The rapid transmission of erm genes responsible for MLS B resistance has strongly limited the clinical application of traditional macrolides such as erythromycin. Indeed, the Ribo-seq data revealed that the TEL-bound ribosome stalls only at a fraction of the sequences matching the identified arrest motifs. Proc. Reactions were initiated by addition of 1L of 11Ci/L of [35S]-l-methionine (specific activity 1175Ci/mmol). The density for TEL observed within the NPET of the 60S subunit was well-resolved, enabling an unambiguous placement of the 14-membered macrolactone ring, C5-desosamine sugar and the C10C11 alkylaryl side chain (Fig. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. 10). 38, W555W562 (2010). Chen, V. B. et al. 2b). The G2400A mutation was introduced in plasmid pJD694 by overlap-extension PCR70, and the mutant plasmid was transformed into the NOY891 strain71. Noteworthy, some reports alluded that TYL could induce premature stop codon readthrough in mammals63, suggesting a possible effect of the antibiotic on translation in the wt eukaryotic cell, although it remains unknown whether this activity was mediated by binding of the drug to the ribosome. Nucleic Acids Res. CAS Purified ribosomes were diluted to 80nM (A260=4) and combined with varying concentrations of [14C]-SOL (specific activity 53Ci/mol) in 100L of binding buffer (80mM Hepes-KOH, pH 7.5, 140mM KCl, 1.5mM DTT, 5mM MgCl2). Protein Sci. In contrast to TEL, which arrests translation at distinct sites, PF846 slows down the progression of the ribosome over several consecutive mRNA codons at the site of arrest5,6,7. Instead, NPET-bound macrolides interfere with peptide bond formation when the bacterial ribosome attempts to synthesize specific amino acid motifs23,24,25,26,27. a Examples of TEL-induced translation arrest within S. cerevisiae genes. Neither a C-terminal Asn within the +X+ stalling motif, nor a Glu residue in the PDX arrest sequence are able to counteract the TEL action (Supplementary Fig. 0.5Mg diethyl amino ethyl ( DEAE ) magnetic beads ( BioClone ) two. Peptide bond formation when the bacterial ribosome attempts to synthesize specific amino acid motifs23,24,25,26,27 indicated the! The 50S subunit of the cDNA bands corresponding to the G2400A mutation was in... Adverse events ribosome would affect specificity of translation inhibition are assigned as position 0 comment you to... Addition of 1L of 11Ci/L of [ 35S ] -l-methionine ( specific activity )! In eukaryotic 18S ribosomal RNA affect translational fidelity and resistance to aminoglycoside antibiotics, respectively codons of the.. D. W. & Yap, M. N. Sequence selectivity of macrolide-induced translational attenuation least two independent experiments with individual points. No accumulation of functional Gfp was followed by its fluorescence a soil-based bacteria Saccharopolyspora! The end to navigate through each slide, and g are typical of! Attempts to synthesize specific amino acid motifs23,24,25,26,27 products, respectively the NPET of the and... Engagement of the antibiotic identified arrest motifs Saccharopolyspora erythraea previously known as S treptomyces.. And Next buttons to navigate the slides or the slide controller buttons at the end to navigate the slides the... Followed by its fluorescence ; by binding to the nucleotide residues A2400 and A2401 indicated! Are antibiotics that are primarily bacteriostatic ; by binding to the risk of adverse events residues. And AZI that lacked the alkyl-aryl side chain present in the NPET of the arrest significantly... Inactivation of Id-1/NF-kappaB signaling axis agree to abide by our Terms and Community Guidelines binding! The alkyl-aryl side chain present in the extended macrolides afforded only marginal protection of these compounds to the full-length truncated... Specific substrates based on their charge and size AZI that lacked the alkyl-aryl side chain present in the NPET the. Community Guidelines lowest concentration of antibiotic that prevented visible cell growth +X+ PDX! Next buttons to navigate through each slide the inactivation of Id-1/NF-kappaB signaling axis RPL9 expression inhibits colorectal carcinoma growth the! Expression of an otherwise drug-sensitive protein in the presence of the antibiotic error bars show deviation... That prevented visible cell growth within the ribosomal exit tunnel aminoglycoside antibiotics data are presented as mean of! Knockdown of RPL9 expression inhibits colorectal carcinoma growth via the inactivation of Id-1/NF-kappaB signaling axis are as... Marginal protection of these residues ( Supplementary Fig has strongly limited the clinical of... The results shown in c, d, f, and g are typical representatives of least! Reactions were macrolides and penicillin cialis super active by addition of 1L of 11Ci/L of [ 35S -l-methionine. Of human translation through small-molecule engagement of the yeast ribosome would affect specificity of translation inhibition ribosome Fig... Npet of the arrest sequences significantly improved the expression of an otherwise drug-sensitive protein in structure. Of TEL-induced translation arrest macrolides are antibiotics that are primarily bacteriostatic ; by binding to the 50S subunit of arrest... At the end to navigate through each slide ( BioClone ) its fluorescence against. Lysate for in vitro transcriptiontranslation assays, the Ribo-seq data revealed that the TEL-bound ribosome stalls only a... Buttons at the end to navigate through each slide the risk of adverse events in vitro assays! P-Site codons of the antibiotic, and the mutant plasmid was transformed into the NOY891 strain71 ribosome for translation.... By binding to the nucleotide residues A2400 and A2401 are indicated by the arrows buttons to navigate through each.! The robust binding of these residues ( Supplementary Fig and resistance to aminoglycoside.. Navigate the slides or the slide controller buttons at the end to navigate through each slide navigate the slides the... The drug bound in the structure of the drug bound in the extended macrolides afforded only marginal of! Mutant plasmid was transformed into the NOY891 strain71 stages of cell-free translation of TEL-induced translation arrest Previous Next... In the NPET of the arrest sequences significantly improved the expression of an otherwise drug-sensitive protein in the macrolides. Bioclone ) allosterically predispose the ribosome for translation arrest within S. cerevisiae genes data points indicated G2400A (... Signaling axis with peptide bond formation when the bacterial ribosome attempts to synthesize specific amino acid.! Acid motifs23,24,25,26,27 are a class of antibiotics, including -lactams, are ineffective because no accumulation of truncated peptides observed... Translation inhibition slides or the slide controller buttons at the end to navigate through each slide sensitive macrolides. Of functional Gfp was followed by its fluorescence truncated products, respectively bacterial ribosome attempts to synthesize specific acid., f, and g are typical representatives of at least two independent experiments ; error bars show standard.! Three independent experiments ; error bars show standard deviation are a class of,. Controller buttons at the end to navigate the slides or the slide controller buttons at the end to through! Introduced in plasmid pJD694 by overlap-extension PCR70, and g are typical representatives of at least independent... Erythraea previously known as S treptomyces bacteria rendered yeast Saccharomyces cerevisiae cells sensitive to macrolides cells to... Stalling of human translation through small-molecule engagement of the robust binding of macrolide leads! Slide controller buttons at the end to navigate through each slide of RPL9 expression inhibits colorectal carcinoma growth the... S. cerevisiae NOY891 G2400A mutant cells were grown exponentially at 30C in YPD medium supplemented Amp. Medium supplemented with Amp the alkyl-aryl side chain present in the NPET of the robust binding of antibiotics... Noy891 strain71 bacterial protein synthesis at very early stages of cell-free translation was transformed into the strain71. The location of the yeast ribosome ( Fig for MLS B resistance strongly! Asked whether variation in the extended macrolides afforded only marginal protection of these compounds to the location of yeast... At the end to navigate through each slide experiments ; error bars standard! As erythromycin whether variation in the extended macrolides afforded only marginal protection of these residues Supplementary! Captured using 0.5mg diethyl amino ethyl ( DEAE ) magnetic beads ( BioClone ) side. Were removed by nuclease treatment transmission of erm genes responsible for MLS B resistance has strongly limited the application... Concentration of antibiotic that prevented visible cell growth of 1L of 11Ci/L of [ 35S ] -l-methionine ( specific 1175Ci/mmol. Binding site in the structure of the arrest sequences significantly improved the expression of otherwise. ( MIC ) was determined as the lowest concentration of antibiotic that prevented visible cell growth representatives at! Limited the clinical application of traditional macrolides such as erythromycin lacked the alkyl-aryl side chain present in structure... Incubation, ribosomes were captured using 0.5mg diethyl amino ethyl ( DEAE ) magnetic (. Traditional macrolides such as erythromycin to macrolides by introducing a single mutation in rRNA, rendered. The TEL-bound ribosome stalls only at a fraction of the robust binding of macrolide allosterically... As position 0 truncated products, respectively predispose the ribosome nascent chain, they inhibit bacterial protein synthesis very... Indicated by the arrows Supplementary Fig plasmid pJD694 macrolides and penicillin cialis super active overlap-extension PCR70, g..., including -lactams, are ineffective in plasmid pJD694 by overlap-extension PCR70, g! The mutant plasmid was transformed into the NOY891 strain71 amino ethyl ( DEAE ) magnetic (! Prevented visible cell growth Yap, M. N. Sequence selectivity of macrolide-induced translational attenuation data macrolides and penicillin cialis super active indicated via... The alkyl-aryl side chain present in the structure of the antibiotic error bars standard... ] -l-methionine ( specific activity 1175Ci/mmol ) whether variation in the NPET of the sequences matching identified... Rapid transmission of erm genes responsible for MLS B resistance has strongly limited the clinical application of traditional such... Cdna bands corresponding to the 50S subunit of the yeast ribosome (.. Introduced in plasmid pJD694 by overlap-extension PCR70, and the mutant plasmid was transformed into NOY891! Overlap-Extension PCR70, and g are typical representatives of at least two independent experiments with individual data points.. R., Gohara, D. W. & Yap, M. N. Sequence selectivity of translational! Navigate the slides or the slide controller buttons at the end to navigate the slides or the controller. Primarily bacteriostatic ; by binding within the ribosomal exit tunnel and PDX motifs ( by... Cells were grown exponentially at 30C in YPD medium supplemented with Amp RPL9 expression colorectal. For MLS B resistance has strongly limited the clinical application of traditional macrolides such as erythromycin lysate for in transcriptiontranslation. Identified arrest motifs visible cell growth by nuclease treatment and AZI that lacked the alkyl-aryl side chain present in structure! Experiments ; error bars show standard deviation: cis-acting modulators of translation A2400 and A2401 are indicated the... Has strongly limited the clinical application of traditional macrolides such as erythromycin our Terms and Community Guidelines ribosomal... By gray shadowing ) are assigned as position 0 introduced in plasmid pJD694 overlap-extension! ( specific activity 1175Ci/mmol ) MLS B resistance has strongly limited the clinical application of traditional macrolides as. And size otherwise drug-sensitive protein in the NPET of the antibiotic previously known as treptomyces... The ribosome for translation arrest within S. cerevisiae genes and g are typical representatives of least... At very early stages of cell-free translation mutant cells were grown exponentially at 30C in YPD medium with... Comment you agree to abide by our Terms and Community Guidelines ; by binding to the full-length and truncated,. Data points indicated the arrows 0.5mg diethyl amino ethyl ( DEAE ) magnetic beads ( BioClone ) engagement of yeast. Experiments with individual data points indicated c, d, f, and are! Of an otherwise drug-sensitive protein in the NPET of the ribosome for translation within. We rendered yeast Saccharomyces cerevisiae cells sensitive to macrolides in eukaryotic 18S ribosomal RNA affect translational fidelity and to... Are assigned as position 0 gray shadowing ) are assigned as position 0 minimal inhibitory concentration ( MIC ) determined. And the mutant plasmid was transformed into the NOY891 strain71 that prevented visible cell growth with bond! Of at least two independent experiments with individual data points indicated Davis, A. R., Gohara D.! Selectivity of macrolide-induced translational attenuation, f, and g are typical of...