Table 1. Comparison of residues in Ca²⁺ binding sites to those in equivalent sites in amphipath transporters  

	SITE I			SITE II
GENE	TM5	TM6	TM8	TM4	TM6
SERCA2	N,E	T,D	E	E	N,D
PMCA4	N,A	M,D	Q	E	N,D
1a	N,Y	F,T	C	I	N,T
1b	N,Y	F,T	C	I	N,T
1c	N,T	Y,T	N	I	N,T
1d	N,T	Y,T	S	I	N,T
1k	N,T	Y,S	T	M	N,S
1m	N,T	Y,T	S	I	N,T
2a	S,S	Y,T	L	I	S,T
2b	G,S	Y,T	L	I	A,T
5b	N,V	F,T	L	I	N,T
5c	N,V	F,S	L	I	N,S
5d	N,V	F,T	L	I	N,T
6f	N, I	F,T	T	V	N,T
6g	N, I	F,T	T	I	N,T
6h	N, I	F,T	T	V	N,T