Biomaterial Database

RNase III cleaves eukaryotic preribosomal RNA at a U3 snoRNP-dependent site. 1996

S A Elela, and H Igel, and M Ares

Biology Department, University of California, Santa Cruz 95064 ,USA.

A yeast gene homologous to bacterial RNase III (RNT1) encodes a double-strand-specific endoribonuclease essential for ribosome synthesis. Two rRNA processing events are blocked in cells temperature sensitive for RNT1: cleavage at the snoRNA-dependent AO site in the 5' ETS and cleavage in the 3' ETS. Recombinant RNT1 protein accurately cleaves a synthetic 5' ETS RNA at AO site in vitro, in the absence of snoRNA or other factors. A synthetic 3' ETS substrate is specifically cleaved at a site 21 nt downstream of the 3' end 28S rRNA. These observations show that a protein endonuclease collaborates with snoRNAs in eukaryotic rRNA processing and exclude a catalytic role for snoRNAs at certain pre-rRNA cleavage.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009711	Nucleotides	The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)	Nucleotide
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004722	Endoribonucleases	A family of enzymes that catalyze the endonucleolytic cleavage of RNA. It includes EC 3.1.26.-, EC 3.1.27.-, EC 3.1.30.-, and EC 3.1.31.-.	Endoribonuclease
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012322	RNA Precursors	RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.	Precursor RNA,Primary RNA Transcript,RNA, Messenger, Precursors,RNA, Ribosomal, Precursors,RNA, Small Nuclear, Precursors,RNA, Transfer, Precursors,Pre-mRNA,Pre-rRNA,Pre-snRNA,Pre-tRNA,Primary Transcript, RNA,RNA Precursor,mRNA Precursor,rRNA Precursor,snRNA Precursor,tRNA Precursor,Pre mRNA,Pre rRNA,Pre snRNA,Pre tRNA,Precursor, RNA,Precursor, mRNA,Precursor, rRNA,Precursor, snRNA,Precursor, tRNA,Precursors, RNA,RNA Primary Transcript,RNA Transcript, Primary,RNA, Precursor,Transcript, Primary RNA,Transcript, RNA Primary
D012331	RNA, Fungal	Ribonucleic acid in fungi having regulatory and catalytic roles as well as involvement in protein synthesis.	Fungal RNA
D012337	RNA, Ribosomal, 18S	Constituent of the 40S subunit of eukaryotic ribosomes. 18S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.	18S Ribosomal RNA,18S RRNA,RNA, 18S Ribosomal,Ribosomal RNA, 18S
D012342	RNA, Small Nuclear	Short chains of RNA (100-300 nucleotides long) that are abundant in the nucleus and usually complexed with proteins in snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR). Many function in the processing of messenger RNA precursors. Others, the snoRNAs (RNA, SMALL NUCLEOLAR), are involved with the processing of ribosomal RNA precursors.	Low Molecular Weight Nuclear RNA,Small Nuclear RNA,snRNA,Chromatin-Associated RNA,Small Molecular Weight RNA,Chromatin Associated RNA,RNA, Chromatin-Associated