Table 1. Summary of FRET biosensors developed.

FRET biosensor	Detects	Family	Inducer of gene expression (fold change)1	Core SBP	Best structural model	Parent vector	Plasmid	ΔFRET on saturation (%)	Ligand bound	Kd (M)
SMb20036-CY	quinic acid	TRAP	D-quinic acid (8.7)	E27-	Class II/	pCYS	pLMB229	−4.7±0.4	D-quinic acid	5.9±1.1×10−9
				Q338	cluster E				shikimic acid	1.0±2.7×10−4
SMb20712-CY	myo-inositol	ABC;CUT2	myo-inositol (6.4)	E22-	Class I/	pCYS	pLMB319	4.7±0.7	myo-inositol	4.7±2.5×10−7
				N309	cluster B
SMc02324-CY/	L-rhamnose	ABC;CUT2	L-rhamnose (>6.2)	E25-	Class I/	pCYS	pLMB291	−5.5±0.4	L-rhamnose	7.3±1.3×10−9
SMc02324-RO			erythritol (>6.2)	F329	cluster B				L-fucose	1.1±0.2×10−5
						pROS	pLMB523	6.4±0.5	L-rhamnose	6.9±1.4×10−9
									L-fucose	1.9±0.5×10−5
SMc02774-CY	L-fucose	ABC;CUT2	D-fucose (6.7)	Q33-	Class I/	pCYS	pLMB292	−4.2±0.4	L-fucose	3.6±1.7×10−9
			pyruvate (4.9)	N329	cluster B				L-rhamnose	1.6±0.6×10−6
			L-fucose (4.2)
SMc04259-CY	β-diglucosides	ABC;CUT1	gentiobiose (19)	T24-	Class I/	pCYS	pLMB345	2.1±0.2	cellobiose	3.3±0.9×10−8
				D441	cluster B				gentiobiose	5.3±2.1×10−8
RL2376-CY	D-galactose	ABC;CUT2	D-arabinose (3.6)	A31-	Class I/	pCYS	pLMB394	5.2±0.4	D-galactose	5.3±1.7×10−6
			D-galactose (2.6)	Y327	cluster B
rcc03024-CY	C4-	TRAP	NA	E27-	Class II/	pCYS	pLMB414	−2.7±0.2	succinate	3.6±0.7×10−8
	dicarboxylates			E333	cluster E				fumarate	5.8±1.2×10−8
									L-malate	7.0±1.4×10−8
									oxaloacetate	1.6±0.6×10−5

¹Inducer of gene expression is taken from [9]. NA: not applicable.