Biomaterial Database

Partial mapping of methylated sequences in Xenopus laevis ribosomal RNA by preparative hybridization to cloned fragments of ribosomal DNA. 1979

B E Maden, and R H Reeder

Xenopus laevis rRNA was hybridised to either of two cloned fragments of ribosomal DNA. One fragment, designated X1r11, contains a short region of the 18 S rRNA gene and most of the 28 S rRNA gene. The other fragment, X1r14, contains a short region of the 28 S gene and most of the 18 S gene. After hybridization the non-complementary rRNA was removed by digestion with T1 RNase and the hybridized RNA was then eluted and examined by fingerprinting analysis. The 3' terminal sequence and the dimethyl-A-containing sequence of 18 S rRNA both hybridized to X1r11 rDNA, in agreement with the known direction of transcription of rDNA. The distribution of other methylated oligonucleotides between the various fingerprints permitted assigment of nearly all of the methylated sequences in 18 S and 28 s rRNA to either the short 3' region or the long 5' region of the respective molecules.

UI	MeSH Term	Description	Entries
D008745	Methylation	Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)	Methylations
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D009843	Oligoribonucleotides	A group of ribonucleotides (up to 12) in which the phosphate residues of each ribonucleotide act as bridges in forming diester linkages between the ribose moieties.
D004274	DNA, Recombinant	Biologically active DNA which has been formed by the in vitro joining of segments of DNA from different sources. It includes the recombination joint or edge of a heteroduplex region where two recombining DNA molecules are connected.	Genes, Spliced,Recombinant DNA,Spliced Gene,Recombinant DNA Research,Recombination Joint,DNA Research, Recombinant,Gene, Spliced,Joint, Recombination,Research, Recombinant DNA,Spliced Genes
D006163	Ribonuclease T1	An enzyme catalyzing the endonucleolytic cleavage of RNA at the 3'-position of a guanylate residue. EC 3.1.27.3.	Guanyloribonuclease,RNase T1,Ribonuclease N1,Aspergillus oryzae Ribonuclease,Guanyl-Specific RNase,RNase Apl,RNase F1,RNase Pch 1,RNase ST,Ribonuclease F1,Ribonuclease F2,Ribonuclease ST,Ribonuclease T-1,T 1 RNase,Guanyl Specific RNase,RNase, Guanyl-Specific,RNase, T 1,Ribonuclease T 1,Ribonuclease, Aspergillus oryzae
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
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
D012265	Ribonucleotides	Nucleotides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)	Ribonucleoside Phosphates,Ribonucleotide,Phosphates, Ribonucleoside
D012270	Ribosomes	Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.	Ribosome
D012335	RNA, Ribosomal	The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)	Ribosomal RNA,15S RNA,RNA, 15S