2.5.1.6 Ca2+ 0.02 mM stimulates activity 685392 2.5.1.6 Co2+ - 639056 2.5.1.6 Co2+ 0.02 mM stimulates activity 685392 2.5.1.6 Co2+ can replace Mg2+ with a lower relative activity, S-adenosylmethionine synthetase B 639048 2.5.1.6 Co2+ can replace Mg2+ with lower relative activity 639048 2.5.1.6 Co2+ for maximal activation the cation concentration must be at least equal to ATP concentration 639045 2.5.1.6 Co2+ high activity in the presence of 20 mM Zn2+ 738285 2.5.1.6 Cs+ - 639056 2.5.1.6 K+ - 639040, 639056, 673793, 674742, 675169, 675572, 676135, 676290, 676530 2.5.1.6 K+ 0.2 mM stimulates activity 685392