TABLE 4.
Stimulation of editing by E. coli tRNAVal with modified 3′-terminal hydroxyl groups
| 3′-Modified tRNAVal | Rate of ATP hydrolysis (pmole/min)a | Relative rate of ATP hydrolysis | Steady-state level of misacylation with threonine (pmole/A260) |
| Ribose derivative | |||
| Adenosine | 745 | (1.0) | 10 |
| 3′-Deoxyadenosine | −14 | −0.02 | 408 |
| 2′-Deoxyadenosine | 1.8 | 0 | 151 |
| 2′,3′-Dideoxyadenosine | 48 | 0.06 | 163 |
| tRNAVal (−A) | −33 | −0.04 | NDb |
| No tRNA | −0.07 | 0 | — |
| Chemically modified ribose | |||
| Adenosineox | −8.0 | −0.03 | ND |
| Adenosineox-red | −1.3 | −0.004 | ND |
| Adenosineox-red + methylamine-borohydride | −9.6 | −0.03 | ND |
| No tRNA | −3.7 | −0.01 | ND |
aNegative values are the result of small variations in the background rate of ATP hydrolysis.
bND, not determined.