Table 1. DDX1 nucleotide binding and hydrolysis.

Equilibrium titrations	(μM)			(μM)
Kd,mantADP	0.12 ± 0.02	Figure 3a	Kd,mantADP (K52A)	31 ± 5	Figure 3b
Kd,mantdADP	0.12 ± 0.03	Supplementary Figure S2
Kd,ADP	0.12 ± 0.03	Figure 3c	Kd,ATP	72 ± 15	Figure 3d
Kd,AppNHp	493 ± 68	Figure 3e	Kd,AppCH2p	284 ± 3	Figure 3f
Transient kinetics	kon (μM−1s−1)	koff (s−1)		(μM)
mantADP	0.95 ± 0.12	0.15 ± 0.0004	Kd,calc (ratio)	0.16 ± 0.21	Figure 4a
mantdADP	0.82 ± 0.04	0.074 ± 0.0001	Kd,calc (ratio)	0.09± 0.01	Figure 4b
RNA-dependent nucleotide binding	(μM)			(μM)
Kd(RNA),mantdADP	0.09 ± 0.02	Figure 5a	Kd(RNA),ATP	5.0 ± 0.8	Figure 5b
Kd(RNA),AppNHp	18 ± 4	Figure 5c	Kd(RNA),AppCH2p	14 ± 5	Figure 5d
RNA binding	(μM)			(μM)
Kd,RNA	2.9 ± 0.9		Kd(AppNHp),RNA	0.4 ± 0.1	Figure 5f
ATP hydrolysis	(μM)			(s−1)
Km,ATP	1750 ± 330		kcat,ATP	0.096 ± 0.005	Figure 6a
Km(RNA),ATP	11.7 ± 1.3		kcat(RNA),ATP	0.168 ± 0.003	Figure 6c
	(nM)
Km(10mM ATP),RNA	70 ± 21		kcat(10mM ATP),RNA	0.141 ± 0.006	Figure 6b
Km(6mM ATP),RNA	107 ± 16		kcat(6mM ATP),RNA	0.168 ± 0.004	Figure 6b
Km(1mM ATP),RNA	257 ± 70		kcat(1mM ATP),RNA	0.222 ± 0.014	Figure 6b

Molecules in subscript and parentheses next to an affinity constant indicate the respective molecule that is present at saturating concentrations. The errors represent the standard error from the fits.