Abstract
We have sequenced a region of cloned Xenopus laevis ribosomal DNA encompassing the last 24 nucleotides of the external transcribed spacer and the first 275 nucleotides of the 18S gene. The start of the 18S gene was identified by correlating the results obtained from RNA hybridization and fingerprinting with the DNA sequence. This 5' region of 18S rRNA contains five 2'-O-methyl groups and at least six pseudouridine residues. Several of these modified nucleotides are clustered into a relatively short region from nucleotides 99-124. Nucleotides 227-250 constitute a distinctive sequence of 24 consecutive G and C residues. Comparison with the first 160 nucleotides of a yeast 18S gene (25) reveals three blocks of high sequence homology separated by two short tracts where homology is low or absent. The external transcribed spacer sequences diverge widely from within a few nucleotides of the start of the 18S gene.
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Selected References
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- Boseley P., Moss T., Mächler M., Portmann R., Birnstiel M. Sequence organization of the spacer DNA in a ribosomal gene unit of Xenopus laevis. Cell. 1979 May;17(1):19–31. doi: 10.1016/0092-8674(79)90291-5. [DOI] [PubMed] [Google Scholar]
- Botchan P., Reeder R. H., Dawid I. B. Restriction analysis of the nontranscribed spacers of Xenopus laevis ribosomal DNA. Cell. 1977 Jul;11(3):599–607. doi: 10.1016/0092-8674(77)90077-0. [DOI] [PubMed] [Google Scholar]
- Brand R. C., Gerbi S. A. Fine structure of ribosomal RNA. II. Distribution of methylated sequences within Xenopus laevis rRNA. Nucleic Acids Res. 1979 Nov 24;7(6):1497–1511. doi: 10.1093/nar/7.6.1497. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brosius J., Palmer M. L., Kennedy P. J., Noller H. F. Complete nucleotide sequence of a 16S ribosomal RNA gene from Escherichia coli. Proc Natl Acad Sci U S A. 1978 Oct;75(10):4801–4805. doi: 10.1073/pnas.75.10.4801. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carbon P., Ehresmann C., Ehresmann B., Ebel J. P. The sequence of Escherichia coli ribosomal 16 S RNA determined by new rapid gel methods. FEBS Lett. 1978 Oct 1;94(1):152–156. doi: 10.1016/0014-5793(78)80926-0. [DOI] [PubMed] [Google Scholar]
- Cox R. A., Thompson R. D. Distribution of sequences common to the 25--28S-ribonucleic acid genes of Xenopus laevis and Neurospora crassa. Biochem J. 1980 Apr 1;187(1):75–90. doi: 10.1042/bj1870075. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eladari M. E., Galibert F. Sequence determination of 5'-terminal and 3'-terminal T1 oligonucleotides of 18-S ribosomal RNA of a mouse cell line (L 5178 Y). Eur J Biochem. 1975 Jun 16;55(1):247–255. doi: 10.1111/j.1432-1033.1975.tb02157.x. [DOI] [PubMed] [Google Scholar]
- Ford P. J., Mathieson T. The nucleotide sequences of 5.8-S ribosomal RNA from Xenopus laevis and Xenopus borealis. Eur J Biochem. 1978 Jun 1;87(1):199–214. doi: 10.1111/j.1432-1033.1978.tb12367.x. [DOI] [PubMed] [Google Scholar]
- Gillespie D., Spiegelman S. A quantitative assay for DNA-RNA hybrids with DNA immobilized on a membrane. J Mol Biol. 1965 Jul;12(3):829–842. doi: 10.1016/s0022-2836(65)80331-x. [DOI] [PubMed] [Google Scholar]
- Hughes D. G., Maden B. E. The pseudouridine contents of the ribosomal ribonucleic acids of three vertebrate species. Numerical correspondence between pseudouridine residues and 2'-O-methyl groups is not always conserved. Biochem J. 1978 Jun 1;171(3):781–786. doi: 10.1042/bj1710781. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Khan M. S., Maden B. E. Nucleotide sequence relationships between vertebrate 5.8 S ribosomal RNAs. Nucleic Acids Res. 1977 Jul;4(7):2495–2505. doi: 10.1093/nar/4.7.2495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Khan M. S., Salim M., Maden B. E. Extensive homologies between the methylated nucleotide sequences in several vertebrate ribosomal ribonucleic acids. Biochem J. 1978 Mar 1;169(3):531–542. doi: 10.1042/bj1690531. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Loening U. E. Molecular weights of ribosomal RNA in relation to evolution. J Mol Biol. 1968 Dec;38(3):355–365. doi: 10.1016/0022-2836(68)90391-4. [DOI] [PubMed] [Google Scholar]
- Maden B. E.H., Forbes J. Standard and non standard products in combined T(1) plus pancreatic RNAase fingerprints of HeLa cell rRNA and its precursors. FEBS Lett. 1972 Dec 15;28(3):289–292. doi: 10.1016/0014-5793(72)80733-6. [DOI] [PubMed] [Google Scholar]
- Maden B. E., Salim M. The methylated nucleotide sequences in HELA cell ribosomal RNA and its precursors. J Mol Biol. 1974 Sep 5;88(1):133–152. doi: 10.1016/0022-2836(74)90299-x. [DOI] [PubMed] [Google Scholar]
- Maxam A. M., Gilbert W. A new method for sequencing DNA. Proc Natl Acad Sci U S A. 1977 Feb;74(2):560–564. doi: 10.1073/pnas.74.2.560. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moss T., Boseley P. G., Birnstiel M. L. More ribosomal spacer sequences from Xenopus laevis. Nucleic Acids Res. 1980 Feb 11;8(3):467–485. doi: 10.1093/nar/8.3.467. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nazar R. N., Sitz T. O., Busch H. Structural analyses of mammalian ribosomal ribonucleic acid and its precursors. Nucleotide sequence of ribosomal 5.8 S ribonucleic acid. J Biol Chem. 1975 Nov 25;250(22):8591–8597. [PubMed] [Google Scholar]
- Petermann M. L., Pavlovec A. The subunits and structural ribonucleic acids of Jensen sarcoma ribosomes. Biochim Biophys Acta. 1966 Feb 21;114(2):264–276. doi: 10.1016/0005-2787(66)90308-x. [DOI] [PubMed] [Google Scholar]
- Sakuma K., Kominami R., Muramatsu M., Sugiura M. Conservation of the 5'-terminal nucleotide sequences of ribosomal 18-S RNA in eukaryotes. Differential evolution of large and small ribosomal RNA. Eur J Biochem. 1976 Apr 1;63(2):339–350. doi: 10.1111/j.1432-1033.1976.tb10235.x. [DOI] [PubMed] [Google Scholar]
- Sanger F., Coulson A. R. The use of thin acrylamide gels for DNA sequencing. FEBS Lett. 1978 Mar 1;87(1):107–110. doi: 10.1016/0014-5793(78)80145-8. [DOI] [PubMed] [Google Scholar]
- Sollner-Webb B., Reeder R. H. The nucleotide sequence of the initiation and termination sites for ribosomal RNA transcription in X. laevis. Cell. 1979 Oct;18(2):485–499. doi: 10.1016/0092-8674(79)90066-7. [DOI] [PubMed] [Google Scholar]
- Sutcliffe J. G. pBR322 restriction map derived from the DNA sequence: accurate DNA size markers up to 4361 nucleotide pairs long. Nucleic Acids Res. 1978 Aug;5(8):2721–2728. doi: 10.1093/nar/5.8.2721. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Trendelenburg M. F., Gurdon J. B. Transcription of cloned Xenopus ribosomal genes visualised after injection into oocyte nuclei. Nature. 1978 Nov 16;276(5685):292–294. doi: 10.1038/276292a0. [DOI] [PubMed] [Google Scholar]