why do the bases orientate themselves to the centre of DNA polynucleotide?

(Original post by 14hasm)
'These are enzymes that cut DNA at specific sites. They are properly called restriction endonucleases because they cut the bonds in the middle of the polynucleotide chain. For example, EcoRI is a restriction endonuclease from E. coli. Some restriction enzymes cut straight across both chains, forming blunt ends, but most enzymes make a staggered cut in the two strands, forming sticky ends (Fig. 13.8).'

Source: https://www.sciencedirect.com/topics...polynucleotide - Scroll to the title 'Evolution and Genetic Engineering'.

I'm not totally sure but I believe it's because each base is connected to its complementary base through a certain number of hydrogen bonds and this possible arrangement makes it easier for certain enzymes to break through bonds.

Hope this helps