InterPro: IPR004960 Bacterial lipid A biosynthesis acyltransferase

Bacterial lipopolysachharides (LPS) are glycolipids that make up the outer monolayer of the outer membranes of most Gram-negative bacteria. Though LPS moleculesare variable, they all show the same general features: an outer polysaccharide which is attached to the lipid component, termed lipid A [1]. The polysaccharide component consists of a variable repeat-structure polysaccharide known as the O-antigen, and a highly conserved short core oligosaccharide which connects the O-antigen to lipid A. Lipid A is a glucosamine-based phospholipid that makes up the membrane anchor region of LPS [2]. The structure of lipid A is relatively invariant between species, presumably reflecting its fundamental role in membrane integrity. Recognition of lipid A by the innate immune system can lead to a response even at picomolar levels. In some genera, such as Neisseria and Haemophilus, lipooligosaccharides (LOS) are the predominant glycolipids [3]. These are analogous to LPS except that they lack O-antigens, with the LOS oligosaccharide structures limited to 10 saccharide units.

The bacterial lipid A biosynthesis protein, or lipid A biosynthesis (KDO)2-(lauroyl)-lipid IVA acyltransferase EC:2.3.1, transfers myristate or laurate, activated on ACP, to the lipid IVA moiety of (KDO)2-(lauroyl)-lipid IVA during lipopolysaccharide core biosynthesis.