23S ribosomal RNA
The 23S rRNA is a 2904 nt long (in E. coli) component of the large prokaryotic subunit (50S) The ribosomal peptidyl transferase activity resides in this rRNA. This is achieved by a base A2486 which the nitrogen at position 3 acts as a base and accepts the H from the amino group of the aa-tRNA in the A site, the aa-tRNA with its free electron (nucleophile) reacts with the carboxyl group of the peptide ester linked to the tRNA in the P site. The Oxygen reforms its double bond and the P site tRNA leaves thanks to the donation of the proton by the adenine base. The adenine base can accept the proton in the first place thanks to several bases with which it coordinates and potassium ion acting as a charge relay. Chloramphenicol binds to A2451 and A2452 residues in the 23S rRNA of the ribosome and inhibits peptide bond formation. Linezolid and quinupristin-dalfopristin also bind to the 23S rRNA and cross-resistance has been demonstrated between these antibiotics.
See also
References
- ^ Mueller F, Sommer I, Baranov P, Matadeen R, Stoldt M, Wöhnert J, Görlach M, van Heel M, Brimacombe R (2000). "The 3D arrangement of the 23 S and 5 S rRNA in the Escherichia coli 50 S ribosomal subunit based on a cryo-electron microscopic reconstruction at 7.5 A resolution.". J Mol Biol 298 (1): 35–59. doi:10.1006/jmbi.2000.3635. PMID 10756104.
- ^ Halic M, Blau M, Becker T, Mielke T, Pool MR, Wild K, Sinning I, Beckmann R (2006). "Following the signal sequence from ribosomal tunnel exit to signal recognition particle.". Nature 444 (7118): 507–11. doi:10.1038/nature05326. PMID 17086193.
External links
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Cytoplasmic
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Mitochondrial
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B bsyn: dna (repl, cycl, reco, repr) · tscr (fact, tcrg, nucl, rnat, rept, ptts) · tltn (risu, pttl, nexn) · dnab, rnab/runp · stru (domn, 1°, 2°, 3°, 4°)
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