Table 1. Initial Velocities of Pi or G6P Import for Various Exchange Substrates.
| His-matGPT1 | His-matGPT2 | ||
|---|---|---|---|
| Pi versus | G6P | 9.9 (100%) | 19.3 (100%) |
| Ru5P | 5.8 (59%) | 14.4 (75%) | |
| 6PG | 0.8 (8%) | 1.2 (6%) | |
| G6P versus | Pi | 10.5 (100%) | 32.6 (100%) |
| Ru5P | 12.2 (116%) | 28.3 (87%) | |
| 6PG | 0.9 (9%) | 3.1 (10%) | |
Time-dependent uptake of [32P]-Pi or [14C]-G6P (0.2 mM) into liposomes reconstituted with total yeast membranes of cells expressing the indicated mature GPT versions (nmol mg−1 total protein). Proteoliposomes were preloaded with 10 mM of G6P, Ru5P, 6PG, or Pi. Relative velocities (given in parentheses) were compared to the counter-exchange experiment Pi/G6P or G6P/Pi, which was set to 100%. Values (bold) are given in percent.