Figure 5.
Residues in the N-terminal region of rPγ affect the Gtα*-GTPγS activation efficiency. A, three N-terminal truncated rPγ mutants (rPγ5–87, rPγ9–87, and rPγ19–87) were reconstituted with Pαβ to test Gtα*-GTPγS activation efficiency. B, three rPγ mutants with internal deletions were tested to evaluate the role of the N terminus in promoting PDE6 activation by Gtα*-GTPγS. C and D, Gtα*-GTPγS activation assays of PDE6, in which rPγ mutants were tested with and without the site-directed mutant V21T. Gtα*-GTPγS activation assays were performed and analyzed as described in Fig. 3A, and the K½ and percent of maximum activation are summarized in Table 1.