Independently of which nucleotide is present when cleaving with MboI, after cleavage with either enzyme, all termini have the central tetranucleotide-GATC . This allows fragments generated with one enzyme to anneal with fragments generated with the other enzyme.
12.
Erwin Chargaff had shown that the base composition of DNA varies by species ( contrary to the tetranucleotide hypothesis ), and in 1952 Rollin Hotchkiss published his experimental evidence both confirming Chargaff's work and demonstrating the absence of protein in Avery's transforming principle.
