Codon recognition

Bertram G, Bell HA, Ritchie DW, Fullerton G, Stansfield I (2000) Terminating errkaryote translation domain 1 of release factor eRFl functions in stop codon recognition. RNA 6 1236-1247 Bidou L, Hatin I, Perez N, Allamand V, Panthier JJ, Rousset JP (2004) Premature stop codons involved in muscular dystrophies show a broad spectrum of readthrough efficiencies in response to gentamicin treatment. Gene Ther 11 619-627... 

Simonson AB, Lake JA (2002) The transorientation hypothesis for codon recognition during protein synthesis. Nature 416 281-285... 

Song H, Mugnier P, Das AK, Webb HM, Evans DR, Tuite ME, Hemmings BA, Barford D (2000) The crystal structure of human eukaryotic release factor eRFl—mechanism of stop codon recognition and peptidyl-tRNA hydrolysis. Cell 100 311-321... 

The aminoglycosides decrease the fidelity of translation by binding to the 30S subunit of the ribosome. This permits the formation of the peptide initiation complex but prohibits any subsequent addition of amino acids to the peptide. This effect is due to the inhibition of polymerization as well as to the failure of tRNA and mRNA codon recognition. Aminoglycosides are ototoxic (i.e., may produce partial deafness), damaging the auditory nerve. Kanamycin is less toxic. Since aminoglycosides are concentrated in the kidney, they may occasionally cause kidney damage. 

Snurce From S. G. Bonitz et al., Codon recognition rules in yeast mitochondria, in Proc. Natl. Acad. Sci. USA 77 3167, 1980. 

During the codon recognition phase another amino acid, for example glycyl-tRNA which has the necessary, correct triplet code moves into the aminoacyl position on the 60s ribosome and bonds with the mRNA and the 40s ribosome when the necessary co-factors, Mg2+, elF 1, elF 2, and GTP, are present. 

SOU D, RajBhandary UL (1967) Studies on polynucleotides. LXXVI. Specificity of tRNA for codon recognition as studied by amino acid incorporation. J Mol Biol 29 113-124... 

In addition to the bases oudined above, transfer RNA (tRNA) (involved in amino acid-specific codon recognition in protein synthesis) contains unusual chemically modified bases (e.g. 

They contain many unusual bases, typically between 7 and 15 per molecule. Some are methylated or dimethylated derivatives of A, U, C, and G formed by enzymatic modification of a precursor tRNA (Section 28.1.8). Methylation prevents the formation of certain base pairs, thereby rendering some of the bases accessible for other interactions. In addition, methylation imparts a hydrophobic character to some regions of tRNAs, which may be important for their interaction with synthetases and ribosomal proteins. Other modifications alter codon recognition, as will be discussed shortly. 

D. V. Freistroffer, M. Kwiatkowski, R.H. Buckingham, and M. Ehrenberg. 2000. The accuracy of codon recognition by polypeptide release factors Proc. Natl. Acad. Sci. USA 97 2046-2051. (PubMed) (Full Text in PMC)... 

During translation in mitochondria, unusual codon recognition is a two out of three base interaction between codon and anticodon. 

Elongation factors Proteins required for bringing the aminoacyl-tRNA to the A-site, codon recognition, and translocation of the newly elongated peptidyl-tRNA from the A-site to the P-site. 

Codon recognition A hydrogen bond forms between the mRNA codon and the anticodon of the next aminoacyl tRNA at the empty A-site of the ribosome. 

Posttranscriptional processing of tRNA requires several distinct steps, as summarized in Figure 25.8. First, the 50 and 30 ends must be cleaved to release the tRNA sequence from the larger precursor transcript and introns must be removed if they are present. Second, the required CCA charging sequence at the 30 end of tRNA must sometimes be added by a nucleotidyl transferase. Third, all tRNAs contain a large number of modified bases which result from reductions, methylations, and deaminations. These modifications can affect codon recognition by the tRNAs during protein synthesis (Chapter 26). 

S. Yokoyama S. Nishimura, Modified Nucleosides and Codon Recognition. In tRNA Structure, Biosynthesis and Function] D. Soil, U. RajBhandary, Eds. ASM Press Washington, DC, 1995 pp 207-224. 

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