RNA(n+1) + phosphate <=> RNA(n) + a ribonucleoside 5'-diphosphate
rna(n+1) + phosphate <=> rna(n) + a ribonucleoside 5'-diphosphate
RNA(n+1) + phosphate <=> RNA(n) + a ribonucleoside 5'-diphosphate
rna(n+1) + phosphate <=> rna(n) + a ribonucleoside 5'-diphosphate