The intron-containing L3 ribosomal protein gene (RPL3): sequence analysis and identification of U43 and of two novel intronic small nucleolar RNAs

Isolation and sequencing of bovine and human intron-containing L3 ribosomal protein genes are here reported. They exhibit very similar organisation, b oth comprising 10 exons and nine introns. A polymorphic locus, involving a 19-bp deletion, was found in intron 6 of the human gene. The frequency of t he two alleles has been estimated in 200 haploid genomes. In bovine and hum an genes intron sequences are rather different, except for limited regions, located in corresponding positions, which show a surprisingly high degree of identity. All these regions contain conserved features defining the box C/D class of small nucleolar RNAs. Demonstration is given that U43 small nu cleolar RNA is encoded within the first intron of both bovine and human gen es. Single nucleotide sequences, encoding two novel species of small nucleo lar RNAs (U82, U83a and U83b), are located in introns 3, 5 and 7. Their exp ression has been investigated and a possible role of these molecules in 2'- O-ribose methylation of rRNAs is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.