Table 1.

Polar interactions between GLP1R and Exe4

GLP1R residue	Location	Exe4 residue	Energy	Mutation	Reduces binding
TM region interactions
T149	TM1	H1	−1.0	T149M (47)	5.0-fold
E387	TM7	H1	−6.2	E387A (48)	3.9-fold
T391	TM7	H1	−2.8	T391A (48)	2.8-fold
K197	TM2	E3	−39.6	K197A (48)	3.0-fold
K383	TM7	E3	−37.9
Q211	EC1	T5	−1.0
Q210	EC1	F6	−3.1
K202	EC1	E17	−48.8
N-terminal interactions
R134	N	E16	−47.6
E128	N	R20	−44.8	E128A (29)	2.4-fold*
E139	N	K12	−38.4
E127	N	K27	−33.4	E127A (29)	6.8-fold*
R40	N	S39	−23.3

Energies are given in kilocalories per mole and are provided to show the relative strength of the interactions.

*Present in the crystal structure of nGLP1R/Exe4.