. Author manuscript; available in PMC: 2010 Jan 16.

Published in final edited form as: J Mol Biol. 2008 Oct 17;385(2):339–349. doi: 10.1016/j.jmb.2008.10.023

Table 3.

Fluorescence, -11 2-AP substituted promoter DNA^a

	a₁^b	k₁ (f, −11) (s⁻¹)^b	a₂^b	k₂ (f, −11) (s⁻¹)^b
WT^c	0.03 ± 0.01	0.39 ± 0.02
T429A	NF^d	NF^d	NF^d	NF ^d
F427A^c	0.014 ± 0.001	0.48 ± 0.01
Y430A	0.27 ± 0.06	0.29 ± 0.01	0.21 ± 0.05	0.07 ± 0.07
W433A^c	0.024 ± 0.004	0.27 ± 0.04
W434A^c	0.019 ± 0.001	0.29 ± 0.01
YW	0.17 ± 0.05	0.34 ± 0.05	0.26 ± 0.02	0.065 ± 0.001
FYW	0.094 ± 0.001	0.13 ± 0.04	0.27 ± 0.01	0.008 ± 0.001
FYWW	0.05 ± 0.01	0.36 ± 0.02

The time-dependence of 2-AP fluorescence as determined in a stopped flow instrument. The final DNA and RNAP concentrations were 10 nM and 50 nM. 600 points were taken over times ranging from 20 seconds to 500 seconds (depending on the RNAP mutant used).

The data were fit to a double exponential equation. The amplitudes (a₁ and a₂) are in arbitrary units.

The data could only be fit to a single exponential.

NF indicates that the data could not be fit to either a single or a double exponential equation due to a low signal.