Table 2 Kinetic constants for ExoS and ExoT ADP-ribosyltransferase domain activity
From: 14-3-3 proteins activate Pseudomonas exotoxins-S and -T by chaperoning a hydrophobic surface
Target | KMεNAD (μM) | KMtarget (μM) | kcat (min−1) | kcat/KM (μM−1 s−1) | |
|---|---|---|---|---|---|
ART domains | |||||
ExoS233–453 | —a | 28.6 ± 6.6 | n.a.b | 9.9 ± 0.72 | 5.7 × 10−3 |
ExoS233–453 | K-Ras | 49.0 ± 9.1 | 32.2 ± 9.9 | 7.9 ± 0.5 | 2.7 × 10−3 |
ExoS233–453 | Rac3 | 41.7 ± 9.3 | 11.4 ± 4.6 | 11.2 ± 0.8 | 4.5 × 10−3 |
ExoS233–453 | Rnd1 | 39.9 ± 18.1 | 4.8 ± 1.9 | 7.9 ± 1.0 | 3.3 × 10−3 |
ExoS233–453 | Agmatine | 133 ± 14 | 2760 ± 130 | 53.5 ± 2.2 | 6.7 × 10−3 |
ExoT235–457 | Crk | 8.2 ± 1.9 | 16.9 ± 2.6 | 2.1 ± 0.10 | 4.3 × 10−3 |
ExoT235–457 | Agmatine | 44.4 ± 5.8 | 660 ± 160 | 0.24 ± 0.01 | 0.1 × 10−3 |
C-terminal deletions | |||||
ExoS233–435 | —a | 61.2 ± 8.9 | n.a. | 7.2 ± 0.4 | 1.9 × 10−3 |
ExoS233–435 | K-Ras | 37.2 ± 2.2 | 17.0 ± 3.1 | 11.7 ± 0.22 | 5.3 × 10−3 |
ExoS233–419 c | —a | 88.5 ± 11.1 | n.a. | n.d.d | n.d. |
ExoS233–419 c | K-Ras | 96.9 ± 18.1 | 36.1 ± 15.7 | n.d. | n.d. |
ExoS-Vis chimaera | |||||
SxVis | — a | 378 ± 81 | n.a. | 0.10 ± 0.01 | 4.4 × 10−5 |
SxVis | K-Ras | 114 ± 19 e | n.d. | 0.42 ± 0.03 | 6.1 × 10−5 |
