Genome organization of retroviruses. III. Restriction endonuclease cleavage maps of mouse sarcoma virus double-stranded DNA synthesized in vitro.

Genome length complementary DNA (cDNA) transcripts were synthesized in vitro by using purified virions of a cloned isolate of mouse sarcoma virus (MSV Clone 124). The cDNA transcripts were converted to double-stranded form by utilizing DNase-digested calf thymus DNA primers and E. coli DNA polymerase I. Restriction endonucleases Sal I, Hind III, Hpa I, Bgl II and Xba I were found to cleave the MSV double-stranded DNA once to generate two fragments, whereas restriction endonucleases Bgl I and Hae II cleaved twice to generate three fragments. Restriction endonucleases E. coli RI and Bam HI did not cleave MSV double-stranded DNA. The order of the restriction fragments was determined in relation to the 5' and 3' ends of the genomic RNA.