Table 1. Kinetic parameters of intrinsic and Gre-stimulated endonuclease reaction catalyzed by the WT and mutant E813A, D814A RNAPs.

			Relative rate
RNAP	GreB	Vmax, min-1	At 10 mM MgCl2	At 60 mM MgCl2	Kd, nM (GreB)	Kd, mM (Mg2+)
WT	WT	25-35*†	2,000-3,500	330-580	170	0.2-0.3
WT	E44Q	0.14-0.16*‡	4-6	1.3-2	100	9-12
WT	D41N	0.3-0.6 × 10-2*‡	0.1-0.12	0.05-0.07	180	15-20
WT	—	1.0-1.3 × 10-2§	1	1	—	>60
ED/AA	WT	3.4-4.6*†	150-200	—	150	0.1-0.3

^*At saturating concentration of MgCl₂.

^†Calculated based on the cleavage rate measured in the presence of 10 nM GreB and K_d (GreB).

^‡The rate measured at 3 μM GreB. All measurements have been performed at pH 7.5, 21°C.

^§At 10 mM MgCl₂.