Nucleotide sequences of 4.5S RNAs associated with poly(A)-containing RNAs of mouse and hamster cells.

The nucleotide sequences of 4.5S RNAs associated with poly-(A)-containing RNAs of mouse and hamster cells were determined. These RNAs have 91 to 94 nucleotides, a high content of G (almost 40%) and no modified nucleoside. The 5'-termini are pppG, but the 3'-termini lack uniformity in the number of uridylate residues. These molecules contain two sets of repeating sequences, and a central purine-rich sequence. There is only one base exchange between mouse and hamster 4.5S RNAs. Possible binding sites of these RNAs to poly(A)-containing RNAs are discussed.