Catalyzes the hydrolysis of UDP-3-O-myristoyl-N-acetylglucosamine to form UDP-3-O-myristoylglucosamine and acetate, the committed step in lipid A biosynthesis. Involved in unsaturated fatty acids biosynthesis. Catalyzes the dehydration of short chain beta-hydroxyacyl-ACPs and long chain saturated and unsaturated beta-hydroxyacyl-ACPs. a UDP-3-O-[(3R)-3-hydroxyacyl]-N-acetyl-alpha-D-glucosamine + H2O = a UDP-3-O-[(3R)-3-hydroxyacyl]-alpha-D-glucosamine + acetate a (3R)-hydroxyacyl-[ACP] = a (2E)-enoyl-[ACP] + H2O Glycolipid biosynthesis; lipid IV(A) biosynthesis; lipid IV(A) from (3R)-3-hydroxytetradecanoyl-[acyl-carrier-protein] and UDP-N-acetyl-alpha-D-glucosamine: step 2/6. In the N-terminal section; belongs to the LpxC family. In the C-terminal section; belongs to the thioester dehydratase family.