30S ribosomal subunit

It has been known for some time that tetracyclines are accumulated by bacteria and prevent bacterial protein synthesis (Fig. 4). Furthermore, inhibition of protein synthesis is responsible for the bacteriostatic effect (85). Inhibition of protein synthesis results primarily from dismption of codon-anticodon interaction between tRNA and mRNA so that binding of aminoacyl-tRNA to the ribosomal acceptor (A) site is prevented (85). The precise mechanism is not understood. However, inhibition is likely to result from interaction of the tetracyclines with the 30S ribosomal subunit because these antibiotics are known to bind strongly to a single site on the 30S subunit (85). 

Carter AP, Clemons WM, Brodersen DE et al (2000) Functional insights from the structure of the 30S ribosomal subunit and its interactions with antibiotics. Nature 407 340-348... 

Brodersen DE, Clemons WM, Carter AP et al (2000) The structural basis for the action of the antibiotics tetracycline, pactamycin and hygromycin B on the 30S ribosomal subunit. Cell 103 1143-1154... 

Alteration in binding site Streptomycin Protein S12 component of 30S ribosomal subunit determines sensitivity or resistance... 

An example of the results that can be obtained using the microtiter format is shown in Fig. 12.5A, which illustrates the inhibition of fMet-tRNA binding to 022 mRNA-programmed 30S ribosomal subunits caused by increasing concentrations of GE81112, the inhibitor of 30SIC formation characterized in Brandi et al. (2006b). 

Kinetics of fMet-tRNA binding to 30S ribosomal subunit Inhibition of ribosomal binding of fMet-tRNA by an antibiotic may reduce the level of initiation complex formed at equilibrium. However, if the effect of the inhibitor consists mainly of slowing down the binding reaction, its effect may appear less dramatic after a relatively long incubation time. For this... 

Brandi, L., Fabbretti, A., Di Stefano, M., Lazzarini, A., Abbondi, M., and Gualerzi, C. O. (2006a). Characterization of GE82832, a peptide translocation inhibitor interacting with bacterial 30S ribosomal subunits, /v Al l 12, 1262—1270. 

DCIA has been used to label numerous proteins and other biomolecules, including phospholipids (Silvius et al., 1987), to study the interaction of mRNA with the 30S ribosomal subunit (Czworkowski et al., 1991), in the investigation of cellular thiol components by flow cytometry (Durand and Olive, 1983), in the detection of carboxylate compounds using peroxyoxalate chemiluminescence (Grayeski and DeVasto, 1987), and for general sulfhydryl labeling (Sippel, 1981). 

Chang, F.N., and Flaks, J.C. (1972) Specific cross-linking of Escherichia coli 30S ribosomal subunit. J. Mol. Biol. 68, 177. 

Czworkowski, J., Odom, O.W., and Hardesty, B. (1991) Study of the topology of messenger RNA bound to the 30S ribosomal subunit of Escherichia coli. Biochemistry 30, 4821. 

Samaha, R.R., Joseph, S., O Brien, B., O Brien, T.W., and Noller, H.F. (1999) Site-directed hydroxyl radical probing of 30S ribosomal subunits by using Fe(II) tethered to an interruption in the 16S rRNA chain. PNAS 96, 366. 

Naturally, the question of whether or not a 27-nucleotide fragment could faithfully mimic the complete 30S subunit had to be answered. Are there nuances to this short stem of RNA binding with paromomycin that do not exist when bound to the intact subunit What role, if any, do neighboring RNA and protein moieties of the ribosome play in binding when the 30S subunit is whole Answers to these questions have become much clearer recently with the ouqtouring of X-ray crystal structures containing aminoglycosides bound to the complete 30S ribosomal subunit. ... 

As the name implies, this class of compounds has four linearly attached six membered rings. Tetracyclines are bacteriostatic and reversibly bind to the 30S ribosomal subunit. They interfere with the binding of aminoacyl tRNA at the A-site of the ribosome. ... 

Ogle JM, Brodersen DE, Clemons Jr WM, Tarry MJ, Carter AP, Ramakrishnan V (2001) Recognition of cognate transfer RNA by the 30S ribosomal subunit. Science 292 897-902 Ogle JM, Murphy FV, Tarry MJ, Ramakrishnan V (2002) Selection of tRNA by the ribosome requires a transition from an open to a closed form. Cell 111 721-732 Ogle JM, Carter AP, Ramakrishnan V (2003) Insights into the decoding mechanism from recent ribosome structures. Trends Biochem Sci 28 259-266... 

Inhibits protein synthesis by binding to the 30S ribosomal subunit, which interferes with binding of aminoacyl-... 

The answer is d. (Hardman, pp 1105—1108.) The bactericidal activity of streptomycin and other aminoglycosides involves a direct action on the 30S ribosomal subunit, the site at which these agents both inhibit protein... 

Tetracycline Prevents bacterial protein synthesis by binding to the 30S ribosomal subunit Bacteriostatic activity against susceptible bacteria Infections caused by mycoplasma, chlamydiae, rickettsiae, some spirochetes malaria H pylori acne Oral mixed clearance (half-life 8 h) dosed every 6 h divalent cations impair oral absorption Toxicity Gastrointestinal upset, hepatotoxicity, photosensitivity, deposition in bone and teeth... 

S ribosomal subunit 50S ribosomal subunit Initiation factors (IF-1, IF-2, IF-3)... 

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