uridine(1939) in 23S rRNA + S-adenosyl-L-methionine = 5-methyluridine(1939) in 23S rRNA + S-adenosyl-L-homocysteine + H(+)
uridine(1939) in 23s rrna + s-adenosyl-l-methionine = 5-methyluridine(1939) in 23s rrna + s-adenosyl-l-homocysteine + h(+)