Table 1.

VS ribozyme cleavage rates measured under standard conditions for different substrates

Substrate	Rate (min−1)	Error (min−1)	Relative decrease
Natural	0.72	0.15	1
A621G	0.018	0.002	40
A622U	3.3 × 10−4	7 × 10−5	2200
A639G	0.42	0.06	1.7
G638A	9.9 × 10−5	9 × 10−6	7300
G638C	9 × 10−5	1 × 10−5	8400
G638U	6 × 10−5	1 × 10−5	12 000
G638 purine	9.0 × 10−5	9 × 10−6	8000
G638 diaminopurine	4.6 × 10−4	2 × 10−5	1600
G6382 aminopurine	8.5 × 10−5	7 × 10−6	8500
G638 inosine	0.026	0.004	27
G638A, C755Aa	8 × 10−5	1 × 10−5	9100
G638A, C755Ga	7 × 10−5	2 × 10−5	9800
G638A, C755Ua	9 × 10−5	3 × 10−5	8200
The rate of cleavage of the G638A substrate was measured using variant ribozyme in which C755 was replaced by adenine, guanine or uracil.