Table 1.

Performance features of MphR biosensor strains with improved ErA sensitivity.

Biosensor	RBS sequencea	Amino acid mutations	Ligand	K1/2 (μM)b	Dynamic rangec	nd
Wild-type	AGAAGGT	-	ErA	1.97 ± 0.03	65,000	3.8 ± 0.3
QCMS-3D6	AGAAGGT	T17R	ErA	0.92 ± 0.03	67,000	3.5 ± 0.2
QCMS-3F8	AGAAGGT	T17A/M59S	ErA	1.43 ± 0.03	64,000	2.5 ± 0.1
QCMS-5B4	AGAAGGT	Q65M	ErA	1.45 ± 0.03	63,000	2.6 ± 0.1
QCMS-5D7	AGAAGGT	T17A/M59E	ErA	1.11 ± 0.02	60,000	2.4 ± 0.1
EP-A3	GGAAGGT	G76C	ErA	0.39 ± 0.02	64,000	2.0 ± 0.1
EP-E7	AGATGGT	V90I	ErA	0.58 ± 0.02	70,000	2.5 ± 0.1
EP-H4	AGAAGGC	R24H/K35N	ErA	0.74 ± 0.03	68,000	2.4 ± 0.1
AA-A3	AGAAGGT	G76C	ErA	1.94 ± 0.02	61,000	3.4 ± 0.1
AA-E7	AGAAGGT	V90I	ErA	2.17 ± 0.3	63,800	3.1 ± 0.1
AA-H4	AGAAGGT	R24H/K35N	ErA	1.88 ± 0.03	63,700	3.6 ± 0.3
RBS-A3	GGAAGGT	-	ErA	0.52 ± 0.02	78,000	1.9 ± 0.1
RBS-E7	AGATGGT	-	ErA	0.64 ± 0.02	74,000	2.0 ± 0.1
RBS-H4	AGAAGGC	-	ErA	1.00 ± 0.02	75,000	2.2 ± 0.1
smRBS-1A1	TTCAGGT	-	ErA	0.19 ± 0.02	70,000	1.7 ± 0.3
smRBS-1G6	CTGAGGT	-	ErA	0.91 ± 0.04	64,000	5.5 ± 1.2
smRBS-2E1	AAAGGTT	-	ErA	1.44 ± 0.08	64,000	3.9 ± 0.5

^aMutated nucleotides are underlined

^bConcentration of ligand at half maximum normalized GFP fluorescence

^cGFP_max – GFP_min

^dHill coefficient, a measure of cooperativity within the MphR biosensor. Values >1 indicate positive cooperativity.