Question of the week_20April

How does a restriction enzyme recognise 2 sites on a double-stranded DNA?

This is really a question I posed to myself. Dun you find it disturbing that an enzyme can cut at two identical sites at the same time? M... or Maybe Not :P

Just to clarify: A RE is usually made up of two identical subunits which will recognise the identical sequences (albeit in opp direction) on the 2 DNA strands to cut them.



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If RE break the phosphodiester bonds, how are the H-bonds broken to, say, linearize the plasmid?

While we need an enzyme to cut the phosphop-bonds, at the temp we work with, the weak H_bonds are broken easily.

If so, wouldn't the two strands of DNA separate totally?

Here is an apt example: If you have one chopstick, you can break it easily. If you have 10?

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