Yeast mitochondrial RNA contains a short polyadenylic acid segment

Abstract

Polyadenylic acid (poly(A)) is present at the 3' terminus of most classes of cytoplasmic messenger RNAs (mRNAs) in all eukaryotic organisms reported so far. Although the role of poly(A) in mRNA function and metabolism is still a subject for speculation, its presence has provided a convenient means for isolation of this class of mRNA by its ability to bind to cellulose and nitrocellulose filters, and to hybridise with matrices containing either oligo(dT) or poly(U). Most poly(A) in cytoplasmic mRNA has been found to be 100-150 nucleotides long, with an electrophoretic mobility of about 7S. The poly(A) segment length of yeast cytoplasmic mRNA is only 50-60 nucleotides, with an electrophoretic mobility of about 4S. mRNA species with still shorter poly(A) segments of only 19-34 residues have been described in the silk moth.