fecosterol + S-adenosyl-L-homocysteine + H(+) => zymosterol + S-adenosyl-L-methionine
fecosterol + s-adenosyl-l-homocysteine + h(+) => zymosterol + s-adenosyl-l-methionine
fecosterol + S-adenosyl-L-homocysteine + H(+) => zymosterol + S-adenosyl-L-methionine
fecosterol + s-adenosyl-l-homocysteine + h(+) => zymosterol + s-adenosyl-l-methionine