preferred_name: a uridine in mRNA + NH4(+) => a cytidine in mRNA + H2O + H(+)
preferred_name_lc: a uridine in mrna + nh4(+) => a cytidine in mrna + h2o + h(+)
label: a uridine in mRNA + NH4(+) => a cytidine in mRNA + H2O + H(+)
label_lc: a uridine in mrna + nh4(+) => a cytidine in mrna + h2o + h(+)