We have constructed hybrid plasmids bearing both Xenopus 5S RNA genes and satellite I sequences in order to test the effect of satellite DNA on 5S gene transcription. Satellite sequences inactivate 5S transcription in both HeLa S100 and Xenopus oocyte microinjection transcription assays. Inactivation of 5S transcription by satellite DNA is observed both in cis and in trans. Transcription of a t...

The nucleotide sequence of the cytoplasmic 5S ribosomal RNA from Scenedesmusobliquus has been determined using post-labelling techniques. The sequence is closely related to the 5S RNA sequence of Chlorella and contains all the areas of invariant sequence which appear to be conserved in plant cytoplasmic 5S RNA species.

Eubacterial rRNA genes are usually organized in opeirons containing the 16S, 23S and 5S rRNA genes, in that order (I). A cluster of structural rRNA genes was discovered during nucleotide sequencing of a cloned 3.6-kb BamiiHI fragment of DNA from B. bacillifornis, the agent of Oroya fever in humans. The 5S rRNA gene is 119 bp in length and is located 107 bases 3' to the 23S rRNA gene of the bact...

Humans express four distinct non-protein-coding Y RNAs (ncRNAs). To investigate Y RNA functional diversification, we exploited an RNA-based affinity purification method to isolate ribonucleoproteins (RNPs) assembled on individual human Y RNAs. Silver staining and mass spectrometry revealed that the Ro and La proteins assemble with all Y RNAs, while additional proteins associate with specific Y ...

This pattern can be explained by assuming that the ancestral, eukaryotic 5S rRNA shared the first two features with the archaebacterlal and eubacterial 5S rRNAs, and that these were altered in the eukaryotic branch of evolution only after the divergence of the red algae, the latter conserving these ancestral features until the present time. As such, the study of 5S rRNA secondary structure cons...

A model for protein synthesis is proposed in which the donor for the peptide elongation reaction is peptidyl-5S RNA. Space-filling models show that peptide bond formation between peptidyl-5S RNA and aminoacyl-tRNA is eminently feasible from a stereochemical point of view. The peptide is transferred to 5S RNA, while at the same time the deacylated tRNA is exchanged by a new aminoacyl-tRNA accept...

The nucleotide sequences of 5S rRNA from two red algae, Gracilaria compressa and Porphyra tenera have been determined. The two 5S rRNAs are fairly dissimilar to each other in their sequences (65% identity), although they are both composed of 121 nucleotides. Their secondary structures are generally of the eukaryotic with a prokaryotic characteristic. Judged from the 5S rRNA sequence data, the r...

Incorporation of somatic histone H1 into chromatin during embryogenesis of Xenopus laevis results in repression of transcription of the oocyte- but not the somatic-type 5S rRNA genes. We showed earlier that a similar effect of the H1 observed in chromatin reconstituted on circular plasmids in vitro depends on its binding to the AT-rich flanks of the oocyte-type 5S rRNA gene. H1 binding results ...

We calculate the decay rate ratios for OZI allowed decays of Υ(5S) to two B mesons by using the decay amplitudes which incorporate the wave function of the Υ(5S) state. We obtain the results that the branching ratio of the Υ(5S) decay to B∗ sB ∗ s is much larger than the branching ratio to BsB ∗ s or BsB ∗ s , in good agreement with recent experimental results of CLEO and BELLE. This agreement ...