Fig. 4.

Position and basal activity of constitutively active P2Y₁₂ mutants. (A) the position of constitutively active mutations in transmembranes 1 and 7 (TM6 and TM7) are depicted. Basal activities of the individual mutants expressed in yeast are given in the table. Data are presented as mean ± S.D. of three independent experiments, each carried out in triplicate. The basal activity of the WT P2Y₁₂ was OD_{600 nm}: 0.074±0.016. Complete functional data are available and organized in a P2Y₁₂ mutant database (http://www.ssfa-7tmr.de/p2y12). (B) the comparative model of P2Y₁₂ based on the CXCR4 template is depicted. Residues producing constitutively active mutants on TM6 and TM7 are highlighted in red. Residue side chains facing the pore of the receptor (F²⁴⁶, F²⁴⁹, and N²⁹⁰) are shown in sticks.