Translation antibiotics inhibiting

Nucleic acids comprise an important category of drug receptors. A number of antibiotics and antirnmor agents either interfere directly with DNA replication or transcription, or inhibit translation of the genetic message at the ribosome level. Certain steroid hormones may also have DNA as their acceptor site (see chapter 8). 

Chloramphenicol Binds to 23S rRNA in the 50S ribosomal subunit and inhibits translation Chloramphenicol acetyl transferase acetylates the antibiotic... 

Neomycin subunit and inhibits translation transferase phosphorylates the antibiotic... 

See also Internal Ribosomal Structure, Translation. Initiation of Translation, Elongation of Translation, Termination of Translation, Antibiotic Inhibition of Translation, Genetic Code, Codons... 

See also Antibiotic Inhibition of Translation, Translation Overview, Structure of tRNAs, Eukaryotic vs Prokaryotic Translation... 

Figure 27.28 shows a few of the important antibiotics that act by inhibiting translation. Many translation-inhibiting antibiotics work selectively on prokaryotic organisms because the process of translation is sufficiently different in them than it is in humans. Thus, these compounds can be used to treat bacterial infections with minimal side effects to humans. 

Provide examples of antibiotics that inhibit translation, and describe their mechanisms of action. 

What could be the signal for the induction of the cold shock proteins It has been observed that shifting E. coli cells from 37 to 5 °C results in an accumulation of 70S monosomes with a concomitant decrease in the number of polysomes [129]. Further, it has been shown that a cold shock response is induced when ribosomal function is inhibited, e.g. by cold-sensitive ribosomal mutations [121] or by certain antibiotics such as chloramphenicol [94]. These data indicate that the physiological signal for the induction of the cold shock response is inhibition of translation caused by the abrupt shift to lower temperature. Then, the cold shock proteins RbfA, CsdA and IF2 associate with the 70S ribosomes to convert the cold-sensitive nontranslatable ribosomes into cold-resistant translatable ribosomes. This in turn results in an increase in cellular protein synthesis and growth of the cells. 

Brandi, L., Fabbretti, A., La Teana, A., Abbondi, M., Losi, D., Donadio, S., and Gualerzi, C. O. (2006b). Specific, efficient, and selective inhibition of prokaryotic translation initiation by a novel peptide antibiotic. Proc. Nat. Acad. Sci. USA 103, 39-44. 

In eukaryotic cells, the number of initiation factors is larger and initiation is therefore more complex than in prokaryotes. The cap at the 5 end of mRNA and the polyA tail (see p. 246) play important parts in initiation. However, the elongation and termination processes are similar in all organisms. The individual steps of bacterial translation can be inhibited by antibiotics (see p. 254). 

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