In enzymology, a N-acetylneuraminate 4-O-acetyltransferase () is an enzyme that catalyzes the chemical reaction acetyl-CoA + N-acetylneuraminate CoA + N-acetyl-4-O-acetylneuraminate Thus, the two substrates of this enzyme are acetyl-CoA and N-acetylneuraminate, whereas its two products are CoA and N-acetyl-4-O-acetylneuraminate. This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is acetyl-CoA:N-acetylneuraminate 4-O-acetyltransferase. This enzyme is also called sialate O-acetyltransferase. References EC 2.3.1 Enzymes of unknown structure