Tetraacyldisaccharide 4'-kinase is an enzyme that phosphorylates the 4'-position of a tetraacyldisaccharide 1-phosphate precursor (DS-1-P) of lipopolysaccharide lipid A. This lipid forms outer membranes of Gram-negative bacteria. This enzyme catalyzes the chemical reaction
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor.