End structure and mechanism of packaging of bacteriophage T4 DNA

We analyzed by restriction enzyme digestion the end structure of T4 phage DNA by comparing mature, concatemeric, first-packaged, and incompletely packaged DNAs. The structure of mature DNA was also studied using 3' end labeling with terminal transferase. Our data support the hypothesis that T4 DNA packaging is not initiated at specific packaging initiation sequences on the concatemeric precursor (cos or pac site mechanisms) but by a different packaging mechanism.