We have established an efficient method for enzymatic production of cytidine 5′- monophospho-N-acetylneuraminic acid (CMP-NeuAc) from inexpensive materials, N- acetylglucosamine (GlcNAc) and cytidine 5′-monophosphate (CMP). The Haemophilus influenzae nanE gene encoding GlcNAc 6-phosphate (GlcNAc 6-P) 2-epimerase and the Campylobacter jejuni neuB1 gene encoding N-acetylneuraminic acid (NeuAc) synthetase, ...