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  • Experiments
  • Immunoprecipitation experiments using antibodies to the TFB1 gene product demonstrate that the transcriptional and CTD kinase activities of factor b are closely associated with an oligomer of the three polypeptides. (sciencemag.org)
  • tRNA
  • While transcription-associated mutagenesis (TAM) has been demonstrated for protein-coding genes, its implications in shaping genome structure at transfer RNA (tRNA) loci in metazoans have not been fully appreciated. (pnas.org)
  • Furthermore, the correlations between tRNA locus variation and transcription indicate that prediction of tRNA gene expression based on sequence variation data is possible. (pnas.org)
  • We present evidence that transcription-associated mutagenesis and strong purifying selection are key determinants of patterns of sequence variation within and surrounding tRNA genes in humans and diverse model organisms. (pnas.org)
  • Furthermore, evolutionary analyses provide strong evidence that tRNA genes, but not their flanking sequences, experience strong purifying selection acting against this elevated mutation rate. (pnas.org)
  • We also find a strong correlation between tRNA expression levels and the mutation rates in their immediate flanking regions, suggesting a simple method for estimating individual tRNA gene activity. (pnas.org)
  • Collectively, this study illuminates the extreme competing forces in tRNA gene evolution and indicates that mutations at tRNA loci contribute disproportionately to mutational load and have unexplored fitness consequences in human populations. (pnas.org)
  • Thus, tRNA molecules are critical for virtually all cellular processes, and the genes encoding tRNA molecules have been highly conserved over evolutionary time ( 1 , 2 ). (pnas.org)
  • However, eukaryotic genomes contain ∼10- to 20-fold as many tRNA genes encoded in their nuclear chromosomes, which are required for cytosolic protein translation ( 2 , 4 ). (pnas.org)
  • Despite their importance to the cell, there has been little study of evolutionary conservation or pathogenic mutations in cytosolic tRNA genes ( 5 , 6 ). (pnas.org)
  • Their 2 rRNA, 22 tRNA and 13 mRNA genes are very useful in phylogenetic studies, in particular the 12S and 16S rRNAs. (wikipedia.org)
  • However, the GC content of ribosomal RNA (rRNA) and transfer RNA (tRNA) genes in hyperthermophiles shows a strong correlation with optimal growth temperature. (wikipedia.org)
  • Noncoding RNA
  • GAS5 noncoding RNA, which accumulates in growth arrested cells, acts as a decoy hormone response element for the glucocorticoid receptor (GR) and hence blocks the upregulation of gene expression by activated GR. A number of studies have linked GAS5 to apoptosis and it may play a role in the progression of some types of cancer. (wikipedia.org)
  • genome
  • InvR was originally predicted by computational screening the genome of Salmonella typhimurium for novel sRNA genes. (wikipedia.org)
  • The smallest RNA viruses in terms of genome size are small retroviruses such as rous sarcoma virus with genomes of 3.5 kilo base pairs (kb) and particle diameters of 80 nanometres (nm). (wikipedia.org)
  • This ncRNA gene was originally identified by computationally searching the genome of the thermophilic archea Methanococcus jannaschii for non-coding regions of high guanine-cytosine (GC) content. (wikipedia.org)
  • The computational screen identified a number of novel ncRNA genes in the genome of M.jannaschii. (wikipedia.org)
  • chromosomes
  • Gene and RefSeq, in collaboration with HGNC, currently describe one 45S rDNA cluster, and one set of 45S precursor and product rRNAs, for each of the five human chromosomes to which these loci are localized. (genecards.org)
  • nuclear
  • Eukaryotes have multiple types of nuclear RNAP, each responsible for synthesis of a distinct subset of RNA. (wikipedia.org)
  • RNA, U2 small nuclear 2 is a protein in humans that is encoded by the RNU2-2 pseudogene. (wikipedia.org)
  • nucleotides
  • RNAP locally opens the double-stranded DNA (usually about four turns of the double helix) so that one strand of the exposed nucleotides can be used as a template for the synthesis of RNA, a process called transcription. (wikipedia.org)
  • RNAP not only initiates RNA transcription, it also guides the nucleotides into position, facilitates attachment and elongation, has intrinsic proofreading and replacement capabilities, and termination recognition capability. (wikipedia.org)
  • in eukaryotes, RNAP can build chains as long as 2.4 million nucleotides (the full length of the dystrophin gene). (wikipedia.org)
  • genomes
  • From genomes that probably originally contained over 3000 genes only about 130 genes remain in the chloroplasts of contemporary plants. (wikipedia.org)
  • MT-RNR1 is one of the 37 genes contained in animal mitochondria genomes. (wikipedia.org)
  • nucleus
  • Over time, the cyanobacterium was assimilated, and many of its genes were lost or transferred to the nucleus of the host. (wikipedia.org)
  • small
  • In humans the RNA component can be one of four small RNAs -- hY1, hY3, hY4 and hY5. (genecards.org)
  • These small RNAs are predicted to fold into a conserved secondary structure containing three stem structures. (genecards.org)