O-(5'-uridylyl)-L-seryl-[protein] + diphosphate => L-seryl-[protein] + UTP
o-(5'-uridylyl)-l-seryl-[protein] + diphosphate => l-seryl-[protein] + utp
O-(5'-uridylyl)-L-seryl-[protein] + diphosphate => L-seryl-[protein] + UTP
o-(5'-uridylyl)-l-seryl-[protein] + diphosphate => l-seryl-[protein] + utp