title: Synthesis of DNAs complementary to human ribosomal RNAs polyadenylated in vitro.
abstract: Conditions are described under which poly(A) polymerase from Escherichia coli ribosomes will catalyse the addition of AMP residues onto the 3'-ends of human 18 S and 28 S ribosomal RNAs at an average rate of 40 AMP residues per 1000 nucleotides in 20 min. Single-stranded complementary DNAs (cDNAs) can then be transcribed from the polyadenylated RNAs with RNA-directed DNA polymerase from avian myeloblastosis virus. All of the sequences in the RNAs are represented in the cDNAs; measurements of the rates at which the cDNAs hybridize with their template RNAs showed that, when appropriate adjustments for differences in lengths and G + C contents of the reacting sequences are taken into account, the Rot 1/2 values of homologous RNA-cDNA hybridization reactions are directly proportional to the base-sequence complexity of the RNAs.
mesh_terms: D004247:DNA / Q000096:biosynthesis*; D004926:Escherichia coli / Q000201:enzymology; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D009691:Nucleic Acid Denaturation; D009693:Nucleic Acid Hybridization; D011061:Poly A / Q000096:biosynthesis*; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D012335:RNA, Ribosomal; D011061:Poly A; D004247:DNA; D011062:Polynucleotide Adenylyltransferase