RNA

About: RNA is a research topic. Over the lifetime, 111695 publications have been published within this topic receiving 5475262 citations. The topic is also known as: ribonucleic acid.

Circular RNA Is Expressed across the Eukaryotic Tree of Life

Abstract: An unexpectedly large fraction of genes in metazoans (human, mouse, zebrafish, worm, fruit fly) express high levels of circularized RNAs containing canonical exons. Here we report that circular RNA isoforms are found in diverse species whose most recent common ancestor existed more than one billion years ago: fungi (Schizosaccharomyces pombe and Saccharomyces cerevisiae), a plant (Arabidopsis thaliana), and protists (Plasmodium falciparum and Dictyostelium discoideum). For all species studied to date, including those in this report, only a small fraction of the theoretically possible circular RNA isoforms from a given gene are actually observed. Unlike metazoans, Arabidopsis, D. discoideum, P. falciparum, S. cerevisiae, and S. pombe have very short introns (∼100 nucleotides or shorter), yet they still produce circular RNAs. A minority of genes in S. pombe and P. falciparum have documented examples of canonical alternative splicing, making it unlikely that all circular RNAs are by-products of alternative splicing or ‘piggyback’ on signals used in alternative RNA processing. In S. pombe, the relative abundance of circular to linear transcript isoforms changed in a gene-specific pattern during nitrogen starvation. Circular RNA may be an ancient, conserved feature of eukaryotic gene expression programs.

Polypeptide Chain Initiation: Nucleotide Sequences of the Three Ribosomal Binding Sites in Bacteriophage R17 RNA

Abstract: The initiator regions of the three cistrons of R17 bacteriophage RNA have been isolated and sequenced. All three regions contain a UGA triplet as well as the expected AUG and two contain the sequence GGUUUGA. The initiator regions thus represent untranslated sequences between termination and initiation codons.

Crystal structure of the RNA-dependent RNA polymerase of hepatitis C virus.

Abstract: We report the crystal structure of the RNA-dependent RNA polymerase of hepatitis C virus, a major human pathogen, to 28-A resolution This enzyme is a key target for developing specific antiviral therapy The structure of the catalytic domain contains 531 residues folded in the characteristic fingers, palm, and thumb subdomains The fingers subdomain contains a region, the "fingertips," that shares the same fold with reverse transcriptases Superposition to the available structures of the latter shows that residues from the palm and fingertips are structurally equivalent In addition, it shows that the hepatitis C virus polymerase was crystallized in a closed fingers conformation, similar to HIV-1 reverse transcriptase in ternary complex with DNA and dTTP [Huang H, Chopra, R, Verdine, G L & Harrison, S C (1998) Science 282, 1669-1675] This superposition reveals the majority of the amino acid residues of the hepatitis C virus enzyme that are likely to be implicated in binding to the replicating RNA molecule and to the incoming NTP It also suggests a rearrangement of the thumb domain as well as a possible concerted movement of thumb and fingertips during translocation of the RNA template-primer in successive polymerization rounds