Expanding the Nucleotide Repertoire of the Ribosome with Post-Transcriptional Modifications

• Published in: ACS chemical biology Vol. 2; no. 9; pp. 610 - 619
• Main Authors: Chow, Christine S, Lamichhane, Tek N, Mahto, Santosh K
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 21.09.2007
• Subjects: Anti-Bacterial Agents - metabolism; Escherichia coli - metabolism; Methylation; Nucleosides - chemistry; Nucleosides - metabolism; Nucleotides - metabolism; Ribosomes - metabolism; RNA Processing, Post-Transcriptional; RNA, Ribosomal - chemistry; RNA, Ribosomal - metabolism; RNA, Ribosomal, 16S - metabolism; RNA, Ribosomal, 23S - metabolism; RNA, Small Nuclear - metabolism; RNA, Transfer - metabolism; Intersubunit bridges: RNA–RNA and RNA–protein interactions at the interface formed upon association of the LSU and SSU during translation; Decoding region: Located on the SSU rRNA and contains highly conserved nucleotides that are involved in interactions with transfer RNAs (tRNAs) and messenger RNA. The A site binds to aminoacyl-tRNA. The P site binds to peptidyl-tRNA; Peptidyl-transferase center: The catalytic center of the ribosome; it is located on the large ribosomal subunit and catalyzes peptide-bond formation and peptide release; Ribosome: Ribonucleoprotein complexes (rRNA and proteins) that manufacture proteins; they contain a small subunit (SSU) and a large subunit (LSU); Pseudouridylation: The isomerization of uridines within RNA to pseudouridine (Ψ) by RNA enzymes known as Ψ synthases; Small nucleolar RNAs: snoRNAs are a class of small noncoding RNA molecules that guide chemical modification (e.g., methylation or pseudouridylation) of eukaryotic rRNAs; Methyltransferases: MTases catalyze highly specific transfer of a methyl group from the cofactor S-adenosyl-l-methionine to the -O, -C, or -N position of a target nucleotide
• ISSN: 1554-8929; 1554-8937
• DOI: 10.1021/cb7001494

In all kingdoms of life, RNAs undergo specific post-transcriptional modifications. More than 100 different analogues of the four standard RNA nucleosides have been identified. Modifications in ribosomal RNAs (rRNAs) are highly prevalent and cluster in regions of the ribosome that have functional importance, have a high level of nucleotide conservation, and typically lack proteins. Modifications also play roles in determining antibiotic resistance or sensitivity. A wide spectrum of chemical diversity from the modifications provides the ribosome with a broader range of possible interactions between rRNA regions, transfer RNA, messenger RNA, proteins, or ligands by influencing local rRNA folds and fine-tuning the translation process. The collective importance of the modified nucleosides in ribosome function has been demonstrated for a number of organisms, and further studies may reveal how the individual players regulate these functions through synergistic or cooperative effects.