Table 2.

Extension rates of unnatural self pairs.^[a]

5'-dTAATACGACTCACTATAGGGAGAX
3'-dATTATGCTGAGTGATATCCCTCTXGCTAGGTTACGGCAGGATCGC
X	kcat [min−1]	KM [µM]	kcat/KM [M−1 min−1]
d3MPy	2.2 ± 0.1	100 ± 3	2.2 × 104
d4MPy	7.5 ± 1.6	36 ± 6	2.1 × 105
d5MPy	6.5 ± 1.1	16 ± 2	4.1 × 105
d34DMPy	1.3 ± 0.08	132 ± 23	9.9 × 103
d35DMPy	6.8 ± 0.9	68 ± 15	1.0 × 105
d45DMPy	15 ± 2	6.2 ± 0.3	2.4 × 106
dQL	0.073 ± 0.007	57 ± 5	1.3 × 103
dEPy	8.6 ± 1.6	102 ± 36	8.4 × 104
dAPy	1.0 ± 0.1	41 ± 2	2.5 × 104
dMAPy	0.77 ± 0.04	123 ± 17	6.3 × 103
dDMAPy	nd[b]	nd[b]	<1.0 × 103

^[a]See Supporting Information for details.

^[b]Reaction was too inefficient for k_cat and K_M to be determined independently.