2'-O-methylcytidine(1920) in 23S rRNA + S-adenosyl-L-homocysteine + H(+) => cytidine(1920) in 23S rRNA + S-adenosyl-L-methionine
2'-o-methylcytidine(1920) in 23s rrna + s-adenosyl-l-homocysteine + h(+) => cytidine(1920) in 23s rrna + s-adenosyl-l-methionine