Table 2:

Properties of the fluorogenic RNA-based sensors discussed in this review

Sensor	Target	EC50 (μM)	Fold activation*	Tested in bacteria	Ref.
Allosteric Spinach	ADP	270	20	Yes	[58]
Allosteric Spinach	SAM	120	25	Yes	[58]
Allosteric Spinach	Adenosine	44	20	No	[58]
Allosteric Spinach	Guanine	1.5	32	No	[58]
Allosteric Spinach	GTP	7,700	15	No	[58]
Allosteric Spinach	c-di-GMP	0.23	(37°C) ~6	Yes	[59]
Allosteric Spinach	c-AMP-GMP	4.2	(37°C) ~8	Yes	[59]
Allosteric Spinach	c-di-GMP	~2	>30	No	[60]
Allosteric Spinach	c-di-GMP	0.005 – 0.4	(37°C) 5 – 7	Yes	[66]
Allosteric Spinach	c-di-AMP	3.4 & 29	2.4 & 9.1	Yes	[67]
Allosteric Spinach	Streptavidin	<0.2	10.3	Yes	[70]
Allosteric Spinach	MCP coat protein	~0.6	41.7	Yes	[70]
Allosteric Spinach	Thrombin	~0.2	6.9	No	[70]
Allosteric Broccoli	c-di-GMP	N/A	~7	No	[48]
Allosteric Broccoli	5-hydroxytryptophan	N/A	>5	Yes	[69]
Allosteric Broccoli	3, 4-dihydroxy phenylalanine	N/A	>5	Yes	[69]
Spinach riboswitch	TPP	9.0	15.9	Yes	[74]
Spinach riboswitch	SAM	1.2	8.8	No	[74]
Spinach riboswitch	Guanine	0.19	6.2	No	[74]
Spinach riboswitch	Adenine	10	4.3	No	[74]
CHARGE	RNA	~0.001	2.2	Yes	[84]
Spinach-Mango FRET	SAM	17	<2	No	[111]

N/A: not available;

^*Fold activation indicates the in vitro sensor performance after adding target as measured at 25°C.