Table 1.

Clusters residue type and frequency in the ligand-binding site of the regulatory domain of QS LuxRs and of the PAB LuxR solos subfamily.

Cluster	Position	QS LuxRs: residue and frequency	QS LuxRs: ligand binding frequency	PAB LuxR solos: residue and frequency
1	57	W (6/6)	16/16	M (13/18), W (5/18)
1	61	Y (6/6)	16/16	W (18/18)
1	70	D (6/6)	2/16	D (18/18)
1	71	P (6/6)	16/16	P (18/18)
1	85	W (6/6)	0/16	W (18/18)
1	113	G (6/6)	16/16	G (18/18)
2	72	V (3/6), I (2/6), T (1/6)	16/16	V (18/18)
2	73	V (3/6), L (3/6)	16/16	Q (18/18)
2	101	F (5/6), L (1/6)	16/16	V (18/18)
2	105	A (6/6)	16/16	L (17/18), M (1/18)
2	110	I (3/6), L (2/6), M (1/6)	16/16	M (15/18), L (2/18), V (1/18)
2	129	S (4/6), T (2/6)	16/16	S (6/18), T (12/18)
3	49	F (2/6), I (1/6), V (1/6), T (1/6), A (1/6)	16/16	M (5/18), K (5/18), E (2/18), S (2/18), L (1/18), V (1/18), Q (1/18), R (1/18)
3	53	Y (6/6)	16/16	A (6/18), T (5/18), I (4/18), L (2/18), V (1/18)
3	58	E (1/6), K (1/6), Q (1/6), R (1/6), L (1/6), V (1/6)	14/16	H (8/18), Q (5/18), R (2/18), L (2/18), A (1/18)
3	62	M (1/6), F (1/6), Q (1/6), D(1/6), L (1/6), I (1/6)	14/16	C (12/18), F (4/18), S (1/18), L (1/18)