why palindromic recognition sequences?

[Steffen Schmidt]

As far as I now,

class II restriction enzymes are homodimers, which bind face to face.
The "normal" B-DNA-form has got about 3.6 bp/turn, i.e. both monomers
recognize the same DNA sequence.

|---><----|
|---><----|
C         G
| T     T |
| | T T | |
| | |x| | |
| | A A | |
| A     A |
G         G
Lars Anders Carlson wrote:

> Could anyone give a reasonable explanation why class II restriction
> enzymes have come to recognise palindromic sequences?
>
> thanks in advance,
>
> Lars Anders Carlson