TABLE 3.
Substrate specificity of recombinant AtSGT1
AtSGT1 proteins (200 ng of either CD1 + CD2, CD1, or CD2) expressed by P. pastoris were incubated at 30 °C for 6 h with four acceptor peptides, and enzymatic products were analyzed by HPLC. Peak areas of substrate and product were calculated, and SGT activity was shown as percentage of the product (the total amount of substrate and product was set as 100% in each experiment). KSOOOO, HSOOOO, SSOOOO, and YSOOOO indicate experiments using FITC-GABA-KSOOOO-NH2 (AtEXTa), FITC-GABA-HSOOOO-NH2, FITC-GABA-SSOOOO-NH2, and FITC-GABA-YSOOOO-NH2, respectively, as the acceptor.
| Expressed region | Activity |
|||
|---|---|---|---|---|
| KSOOOO | HSOOOO | SSOOOO | YSOOOO | |
| % | ||||
| CD1+CD2 | 63.2 | 19.6 | 49.0 | 94.1 |
| CD1 | 12.1 | 6.1 | 15.8 | 57.4 |
| CD2 | 90.7 | 27.0 | 17.2 | 24.9 |