Cleavable C-terminal fusion proteins

[Jon Hobman]

Hi netters.

I wonder if anyone knows of an expression vector that has a C-terminal tag 
(such as 6x His) that has a specific protease cleavage site between your 
protein and the tail. I've found loads of N-terminal cleavable fusion tags but 
I want to tag a periplasmic metal binding protein which has a cleaved leader 
sequence (hence no N-term tags) and we are concerned that a big nickel binding 
hexapeptide might well alter dramatically the metal binding propeties of the 
protein (hence removal of the tag). Also has anyone tried carboxypeptidase A 
to remove their C-term tags and has it worked?

Thanks in advance 

Dr JON