Nucleotide sequence of 5S ribosomal RNA from the posterior silk glands of Bombyx mori.

A low molecular weight RNA fraction was obtained from the posterior silk glands of Bombyx mori. 5S rRNA was purified from this fraction by gel filtration on a column of Sephadex G-100 and electrophoresis on a discontinuous polyacrylamide gel devised for large scale preparation. The nucleotide sequence of this RNA was determined mainly by a chemical sequencing method on polyacrylamide gels using RNA labeled with [32P]pCp at the 3' terminus (1). An enzymatic sequencing method on gels using 32P-labeled RNA at the 5' end (2) and conventional sequence analyses of the complete digests of the unlabeled RNA with RNase T1 [EC 3.1.27.3] and RNase A [EC 3.1.27.5] were used for complete determination of the total sequence. 16 base substitutions were observed between B. mori and Drosophila melanogaster 5S rRNAs.