L-serine + diphosphate <=> O-phospho-L-serine + phosphate + H(+)
l-serine + diphosphate <=> o-phospho-l-serine + phosphate + h(+)
L-serine + diphosphate <=> O-phospho-L-serine + phosphate + H(+)
l-serine + diphosphate <=> o-phospho-l-serine + phosphate + h(+)