Nucleotide sequence of Xenopus laevis 18S ribosomal RNA inferred from gene sequence.

18S ribosomal RNA in Xenopus laevis is 1,825 nucleotides long, as inferred from sequence analysis of an 18S gene. All the 40 rRNA methyl groups can be located in the sequence. Comparison with the yeast (Saccharomyces cerevisiae) 18S sequence reveals extensive regions of high homology interspersed with tracts having little or no homology. Regions of high homology contain almost all the RNa methyl groups. Major regions of low homology area considerably richer in C + G in Xenopus than in yeast.