FIGURE 9.

Probing the side chain effect at Ser²⁷² of EC3 on constitutive signaling of C5aR in yeast. The constitutive signaling profile of S272T, S272A, and S272C mutants in the presence and absence of S30C at the N terminus of C5aR. Maximal signaling is noted for all the single and double mutants in response to C5a. Vector represents the β-galactosidase activity of the engineered yeast in the absence of both receptor and ligand. Each bar represents means ± S.D. of signaling activity for three independent transformants, and data are representative of at least two independent experiments.