how do restriction endonuclweases work?

[Wolfgang Schechinger]

Hi all there! No, don' tell me: "they cut DNA at specific sites". 
What I want to know is: HOW DO THEY FIND THIS SITE!

Are they walking along the DNA (where do they bind initially?) until 
they think that it might be a good place to bite or are they 
attracted magically by the restriction site thus they approach 
like from outer space and hit the DNA just at the right place?

What happens after the cut? Does the RE fall off immediately or 
does it still remain attached to the DNA (how much space -base 
pairs?- do they consume) and will it -in the end- be able to block 
another -different species- of RE to cut near this site?

Just my last nightmare.

I'm keen your comments and ideas!

Wolfgang
---------!all possible disclaimers apply!-----------
                                     
Wolfgang Schechinger
University of Tuebingen
email: wgschech at med.uni-tuebingen.de

http://www.medizin.uni-tuebingen.de/~wgschech/research.htm

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