Table 3. Sensor residues in TtAgo ternary complex.

Index	Type	SASA	Salt bridge
51	Arg	127
52	Arg	118
76	Glu	111	Arg89
114	Arg	93	Asp154
115	Arg	18
130	Glu	23	Arg172*, Arg199*
166	Glu	50
172	Arg	37	Glu130
0191	Lys	135	Glu203
192	Arg	94	Glu203
194	Arg	26
199	Arg	110	Glu130
200	Arg	181	Asp198
203	Glu	10	Lys191*, Arg192*
246	Asp	81
248	Lys	157
249	Asp	75	Arg251
268	Glu	79
269	Asp	64
289	Arg	95	Glu285
335	Arg	96	Glu448
340	Arg	142
478	Asn	0
482	Arg	152
517	Glu	92
521	Asp	39	Arg513
546	Asp	19
548	Arg	44
552	Asp	133
553	Glu	37
574	Arg	119
575	Lys	84
597	Glu	94	Arg13
598	Asp	147
608	Arg	64
609	Asp	96
611	Arg	42
618	Lys	49
640	Arg	23	Asp590
651	Arg	9
660	Asp	15
661	Arg	29
665	Glu	8	Arg418, Arg668
672	Arg	204
685	Val	13

Solvent-accessible surface area, reported in Ų, was calculated with a probe radius of 1.4 Å. Certain sensor residues are taken to form salt bridges by distance (O–N distance cutoff 3.2 Å in the 3F73 crystal structure); asterisks denote salt bridges between sensor residues.