Table 1. The nucleotide bias at each position of the T7 promoter library.

Position	Original base	G (%)	A (%)	T (%)	C (%)
-17	T	9.5	9.6	73.6	7.3
-16	A	11.5	66.6	12.9	9.0
-15	A	11.2	66.9	13.7	8.2
-14	T	9.5	9.0	73.8	7.7
-13	A	10.3	67.3	12.9	9.5
-12	C	13.2	11.7	13.7	61.3
-11	G	69.9	9.8	12.4	7.9
-10	A	11.0	66.1	13.1	9.8
-9	C	12.2	11.9	15.6	60.3
-8	T	9.6	8.9	73.9	7.6
-7	C	11.9	12.2	14.3	61.6
-6	A	10.7	66.8	13.3	9.2
-5	C	11.8	12.2	15.8	60.3
-4	T	10.1	10.4	72.3	7.2
-3	A	11.2	65.7	14.8	8.2
-2	T	10.1	11.0	72.3	6.6
-1	A	12.4	66.8	12.8	8.0
1	G	70.5	10.1	11.9	7.5
2	G	67.5	12.2	12.5	7.8