3.5.1.23	Ba2+	better activator than Mg2+	657260	
3.5.1.23	Ca2+	-	680936, 696396, 699000	
3.5.1.23	Ca2+	a calcium or magnesium ion is presumed to be important for stabilizing the two domains	733408	
3.5.1.23	Ca2+	ACER isoform activities are enhanced by Ca2+	719197	
3.5.1.23	Ca2+	ACER3 has a catalytic Zn2+ binding site in its core and a Ca2+ binding site physically and functionally connected to the Zn2+, two residues appear to play critical roles in physically linking the Ca2+ and the Zn2+ sites, W20 and E33. E33 carboxylate interacts with the Ca2+ ion and is in close proximity to H81TM2 side chain, while H81TM2 coordinates the Zn2+, Ca2+-binding site within the N-terminus, structure overview. The Ca2+ ion is coordinated by six oxygens from the D19 carboxylate (bidentate), the W20 backbone carbonyl, the E22 backbone carbonyl, the N24 side chain carbonyl, and the E33 carboxylate (monodentate)	754856	
3.5.1.23	Ca2+	activates	667523, 733984, 755487	
3.5.1.23	Ca2+	activates, required by ACER2 for both its in vitro and cellular activities. Cellular ACER2 activity is inhibited by depletion of Ca2+ from Golgi lumen	712496	
3.5.1.23	Ca2+	after EDTA treatment, Ca2+ reestablishes activity completely	171990	
3.5.1.23	Ca2+	Ca2+-dependent, better activator than Mg2+	657260	
3.5.1.23	Ca2+	enhances activity	700748