Length and position of HisTags can affect the following:
- Expression Yield
- Efficiency of translation. Triplet codons located after ATG can inhibit translation. Use highest expressing AAA (Lysine) at position 2
- Binding to IMAC resin
- Results (activity, crystallization, NMR …etc). Remove the tag!
- Oligomerization state
E.coli water channel AqpZ expression and purification using different His-Tags (Co = cobalt-IMAC, & subsequent Q2= ion-exchange).