A αTub84B promoter drives expression of wts that has been mutated to carry a K749R amino acid substitution (predicted to result in a kinase-dead protein), and which is tagged at the N-terminal end with Citrine and at the C-terminal end with mTFP1. mTFP1 and Citrine can act as a fluorescence resonance energy transfer (FRET) pair (donor and acceptor respectively), and changes in the quenching ratio (acceptor channel emissions/donor channel emissions) can be used to monitor conformational changes in the mutant wts protein in vivo. Generated by excision of the FRT cassette in wtsK749R.αTub84B.FRT.CWT.