. 2005 May;25(9):3583–3595. doi: 10.1128/MCB.25.9.3583-3595.2005

TABLE 1.

Values for apparent reaction rates k_a, k_b, k_c, and k_d, and *A43 · GTP → A43 isomerization reversal (IR) are indicated for TFIIF, TFIIF 74(1-227), and TFIIF 74(1-158)

Factor	k_a (s⁻¹)	k_b (s⁻¹)^a	k_c (s⁻¹)	k_d (s⁻¹)	IR (%)^c
TFIIF + TFIIS^b	33 ± 4	1,450 ± 240	1.0 ± 0.2	27 ± 4	41
TFIIF74(1-227) + TFIIS	35 ± 6	1,300 ± 180	1.0 ± 0.1	31 ± 4	21
TFIIF74(1-158) + TFIIS	7.6 ± 0.9	760 ± 250	0.3 ± 0.04	7.6 ± 0.9	21

k_b rates are too high to be measured reliably with the RQF-3 at 25°C, and so apparent differences in k_b may not be meaningful (43).

From reference 43.

X. Gong, C. Zhang, M. Feig, and Z. Burton, unpublished data.