期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：6
页码：2389-2393
DOI：10.1073/pnas.74.6.2389
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The initiation of DNA synthesis in vitro by RNA-directed DNA polymerase (deoxynucleosidetriphosphate: DNA deoxynucleotidyltransferase, EC 2.7.7.7 ) of avian oncornaviruses requires a tRNAtrp primer molecule located close to the 5' end of the viral RNA genome. DNA transcripts, 100 nucleotides in length, initiated on the tRNAtrp primer molecule contain nucleotide sequences complementary to a large (25 nucleotides) RNase T1 oligonucleotide, T-13, located at the 5' terminus of the avian sarcoma virus RNA genome. tRNAtrp-initiated DNA transcripts with a length of about 70 nucleotides contain substantially fewer nucleotide sequences complementary to this 5'-terminal oligonucleotide, suggesting that the tRNAtrp primer associated with the avian sarcoma virus RNA is located approximately 100 nucleotides from the 5' end of the RNA. In addition, we present evidence to demonstrate that DNA transcribed from avian sarcoma virus RNA sequences located at the 3' end, immediately adjacent to the poly(A), contains nucleotide sequences that are complementary to the 5'-terminal T1 oligonucleotide T-13. These data indicate that the 5' end of the viral genome contains nucleotide sequences that are repeated at the 3' end of the genome. We conclude that the avian oncornavirus RNA genome is terminally redundant.
