Flag-tag protein - Need advice for Flag-tag protein (Oct/05/2004 )

I am going to do a flag-tagged protein expression and purification. My final goal is to get the structure of this protein. I want to know if Flag-tag is a good tag for protein purification.

Looking forward to hearing from somebody.

as a flag-tag can be used for purification under native conditions, this COULD be ok. nobody can guanantee you that a specific protein will work together with a specific tag. you should mind that the binding of the flag-tag is Ca-dependent and therfore EDTA sensitive. So don't add EDTA to your wash-buffer!

maybe you could consider a strep-tag as an alternative, but you could go with the flag-tag first.

often protein cristallographers use the his-tag in variant sizes (4x - 10x His), but the proteins is denatured in the process of elution and has to be refolded for structure determination.

mike