Nucleotide sequences of integrated Moloney sarcoma provirus long terminal repeats and their host and viral junctions

Integrated Moloney murine sarcoma provirus (MSV) has direct terminal repeat sequences (TRS). We determined the nucleotide sequence of both 588-base-pair TRS elements and the adjacent host and viral junctions of an integrated MSV cloned in bacteriophage λ. Sequences were identified corresponding to the tRNA (pro) primer binding site in genomic RNA and the reverse-transcribed minus strong stop DNA. Each 588-base-pair repeat contains putative sites for promoting RNA synthesis and RNA polyadenylation. The first and last 11 nucleotides of the TRS are inverted with respect to each other, and the same four-nucleotide host sequence is found bracketing integrated MSV. Some similarities of TRS and prokaryotic insertion sequence elements are discussed.