Table 1.

Thermodynamic parameters of the binding between N and their cognate Ubl1 in three CoVs.

Substrate	Ligand	Kd (μM)	n	ΔH (kJ/mol)	ΔS (J/mol·K)
SARS-CoV-2
N	Ubl1	0.8 ± 0.2	1.19 ± 0.02	−62.5 ± 2.6	−99.0
Ubl1	N-arm–NTD–LKR	0.7 ± 0.2	0.60 ± 0.02	−33.7 ± 1.9	0.9
Ubl1	NTD–LKR	0.8 ± 0.2	0.64 ± 0.01	−34.5 ± 1.2	−2.5
Ubl1	NTD	17.0 ± 4.2	0.73 ± 0.03	−11.3 ± 1.2	52.3
Ubl1	CTD–C-tail	N.D.a	-	-	-
Ubl1	NTD R92A	55.7 ± 16.3	0.58 ± 0.11	−13.3 ± 3.2	35.5
Ubl1 E26A	NTD	78.6 ± 25.3	0.74 ± 0.04	−14.1 ± 1.7	29.7
Ubl1 E95A	NTD	53.1 ± 18.2	0.75 ± 0.08	−5.2 ± 1.2	63.8
Ubl1 Y103A	NTD	57.7 ± 22.4	0.57 ± 0.05	−3.1 ± 0.6	70.5
Ubl1 D110A	NTD	50.8 ± 14.3	0.64 ± 0.06	−11.1 ± 0.8	44.0
SARS-CoV
N	Ubl1	0.8 ± 0.2	1.00 ± 0.02	−55.9 ± 1.6	−76.2
MERS-CoV
N	Ubl1	2.3 ± 0.6	0.82 ± 0.02	25.5 ± 1.3	196.0

^aN.D.: not determined.