label: a 5-methylcytidine in rRNA + S-adenosyl-L-homocysteine + H(+) => a cytidine in rRNA + S-adenosyl-L-methionine
label_lc: a 5-methylcytidine in rrna + s-adenosyl-l-homocysteine + h(+) => a cytidine in rrna + s-adenosyl-l-methionine