Table S1.

Parameters for each round of in vitro evolution

Round	Method	Nt added	Time (h)	Primer	Template	Splint	Mut
1	gel	20	24	SP1	T-R0	Spl1
2	gel	20	24	SP1	T-R0	Spl1
3	gel	20	24	SP1	T-R0	Spl1
4	gel	20	24	SP1	T-R0	Spl1	+
5	apt	12	4	SP2	T-B12	Spl2
6	apt	12	4	SP2	T-B12	Spl2
7	apt	12	4	SP2	T-B12	Spl2
8	gel	18	24	SP3	T-B12	Spl2
9	gel	18	24	SP3	T-B12	Spl2
10	gel	18	24	SP3	T-B12	Spl2
11	gel	18	24	SP3	T-B12	Spl2
12	gel	18	24	SP3	T-B12	Spl2	+
13	gel	30	2	SP4	T-GTP	Spl3
14	gel	30	2	SP4	T-GTP	Spl3
15	gel	30	2	SP4	T-GTP	Spl3
16	gel	30	2	SP4	T-GTP	Spl3
17	gel+apt	30	2	SP4	T-GTP	Spl3	+
18	gel	32	6	SP1	T-R12	Spl1
19	gel	32	1	SP1	T-R12	Spl1
20	gel	32	0.25	SP1	T-R12	Spl1
21	gel	40	0.25	SP1	T-R20	Spl1
22	gel+apt	30	0.25	SP4	T-GTP	Spl3	+
23	gel+apt	30	0.25	SP4	T-GTP	Spl3
24	gel+apt	30	0.25	SP4	T-GTP	Spl3

The selection method involved gel-shift (gel) and/or aptamer capture (apt), following polymerase extension of 12–40 nt for 0.25–24 h. See Table S4 for sequences of primers, templates, and splints. Mutagenic PCR was performed after certain rounds, as indicated by +.