Two mutants of TxtE were generated by site-directed mutagenesis.

For the first mutant, the Tyr residue at position 89 of TxtE was mutated to a Phe residue. This is referred to as the Y89F protein.

For the second mutant, the Asn residue at position 293 of TxtE was mutated to a Leu residue. This is referred to as the N293L protein.

Equilibrium dissociation constants (K_d) values were obtained for the wild-type, Y89F protein, and N293L protein and are shown in the table below. Which of the three proteins exhibits the lowest affinity for Trp?

Protein	Kd (M)
Wild-type	44
Y89F	120
N293L	1700

Choose from:

1. Y89F protein

2. N293L protein

3. wild-type