TABLE 1.

Effects of substitutions in σ³² on its ability to bind core RNAP

Substitution in σ32	Bound σ32 (% of wt)a
None (wt)	100
R92A	166 ± 16
F104A	20 ± 8
F104H	20 ± 3
W108A	92 ± 6
A111Q	42 ± 6
Y116A	115 ± 12
F136A	42 ± 2
E265A	170 ± 15
R266A	89 ± 27
R268A	62 ± 2
Q269A	102
L270A	33 ± 4

^aAll values have been normalized to the extent bound for wt σ³² (10% to 30% of total detectable σ³² in different experiments). Averages of duplicates are shown ± half the spread; values of the duplicates were the same for Q269A.