Mapping of inverted repeated DNA sequences within the genome of simian virus 40.

Abstract

Single-stranded, linear DNA of SV-40 created by denaturing the endonuclease EcoRI- or Hpa II-generated, linear, double-stranded products from form I DNA of SV-40 was analyzed for regions of inverted repeated sequences by visualization with Em. Six hairpin loops were found at positions 0.11-0.30 (2 loops forming a rabbit ears structure), 0.47-0.52, 0.63-0.68, 0.70-0.76 and 0.90-0.96. The nucleotide sequences within all of these inverted repeats may be related since the looped regions can crosshybridize with one another; thus, the SV-40 genome may contain regions of interspersed repeated and unique sequences. The map positions of the 3'' and 5'' ends of the early and late messenger RNAs, as determined by others, lie within regions of inverted repeated sequences. Previously recorded recombination events that occurred within the SV-40 genome or between SV-40 DNA and other genomes apparently occurred frequently at positions of inverted repeated sequences within the SV-40 DNA.