blunt end restriction out of recognition site

[snusnu]

Hi all,

I'm looking for a restriction enzyme that will make blunt cleavage out of it's recognition site.

For example:
if the recognition site is: CAAT
and the sequence is: CAGACAATGCT
GTCTGTTACGA
The resulting cleavage will be something like: CAGA....CAAT....GCT
GTCT....GTTA....CGA

Can any one help me out?
Thank!

[nkukushkin]

I don't think something like that exists. Why can't you use normal blunt cleavage? Alternatively, if you are talking about digesting a plasmid, you can run a long PCR with primers terminating with (in your example) 5'-GCT.....-3' and 5'-TCTG....-3'. This way you will get the desired blunt linear DNA (provided you use proofreading polymerases) missing the CAAT fragment.