I have a question concerning removal of a his-tag sequence.
We have crystallized a protein with an important feature at the C-terminal
part of the protein.
Unfortunately, we cannot express it with a N-terminal his-tag, only with a
C-terminal his-tag.
Therefore we are looking for a protease which cleaves off the sequence
without leaving any extra amino acid on the C-terminus of our protein.
Meaning we obtain really the wild type protein.
Does anyone know about a protease or cleavage site which is completely
removed?
C-terminal intein fusion is a self-cleavable tag that cuts cleanly. NEB
sells kit for intein-chitin binding domain fusion for affinity purification
but of course you can add any other tag of your liking.
- Dima
