In enzymology, a lipopolysaccharide N-acetylmannosaminouronosyltransferase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are UDP-N-acetyl-beta-D-mannosaminouronate and lipopolysaccharide, whereas its two products are UDP and N-acetyl-beta-D-mannosaminouronosyl-1,4-lipopolysaccharide.
This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-N-acetyl-beta-D-mannosaminouronate:lipopolysaccharide N-acetyl-beta-D-mannosaminouronosyltransferase. Other names in common use include ManNAcA transferase, uridine-diphosphoacetylmannosaminuronatetranferase, N-acetylglucosaminylpyrophosphorylundecaprenol glucosyltransferase, and acetylmannosaminuronosyltransferase.