The Length of the Terminal Repetition in Adenovirus-2 DNA

Adenovirus-2 DNA was end-labeled by partial digestion with Escherichia coli exonuclease III and resynthesis with the DNA polymerase from avian myeloblastosis virus and α-³²P-labeled deoxyribonucleoside triphosphates. This end-labeled DNA was cleaved with several specific endonucleases and the terminal fragments were characterized by gel electrophoresis and pyrimidine tract analysis. Two endonucleases gave identical fragments from both ends, presumably from cleavage within the inverted terminal repetition, while all other endonucleases gave dissimilar fragments from the two ends. From the sizes of these fragments it is estimated that the inverted terminal repetition is between 100 and 140 nucleotide pairs long.