Cautionary tail: the presence of an N-terminal tag on dynein light-chain Roadblock/LC7 affects its interaction with a functional partner.

As part of structural investigations of components of the molecular motor, dynein, we prepared the light chain, Robl1_mouse, with and without an N-terminal His-tag. We found that the His-tag introduced a spurious binding site for a second protein, IC74. We propose a molecular mechanism for functional interference by the His-tag.