the enzyme is necessary for the biosynthesis of lipid A, which comprises the outer leaflet of the outer membrane in Gram-negative bacteria. The enzyme has important effects on virulence in many human and animal pathogen
a strain E058 lpxM mutant lacks one myristoyl (C14:0) on its lipid A molecules. No differences are observed between the mutant and wild-type in growth rate in different broths and ability to survive in specific-pathogen-free chicken serum. The mutant strain shows significantly reduced invasion and intracellular survival in the avian macrophage HD11 cell line. HD11 cells treated with E058 lpxM-mutant derived lipopolysaccharide also show reduction of nitric oxide production and downregulation of cytokine gene expression. Compared to the parental strain, the mutant leads to a significant reduction in bacterial load in heart, liver, spleen, lung, and kidney tissues. The histopathological lesions in visceral organs of birds challenged with the wild-type strain are more severe than in birds infected with the mutant. The mutant shows a sensitivity pattern similar to the parental strain following exposure to several hydrophobic reagents
lipid A structures of lpxM and lpxP mutants lack the secondary lauroyl 12:0 group (R3'') or palmitoleoyl 16:1 group (R2''), respectively, and thus both represent a pentaacyl lipid A. Lipid A of Yersinia pestis lpxM/lpxP double mutant lacks both secondary acyl groups, 12:0 and 16:1, and is thus represented by the tetraacyl form. The absence of at least one acyl group is crucial for binding of lipopolysaccharide to toll-like receptor TLR4. Lipopolysaccharide from lpxM and and lpxP mutants induces TNF production at approximately the same level, the former being a slightly stronger activator than the latter
a strain E058 lpxM mutant lacks one myristoyl (C14:0) on its lipid A molecules. No differences are observed between the mutant and wild-type in growth rate in different broths and ability to survive in specific-pathogen-free chicken serum. The mutant strain shows significantly reduced invasion and intracellular survival in the avian macrophage HD11 cell line. HD11 cells treated with E058 lpxM-mutant derived lipopolysaccharide also show reduction of nitric oxide production and downregulation of cytokine gene expression. Compared to the parental strain, the mutant leads to a significant reduction in bacterial load in heart, liver, spleen, lung, and kidney tissues. The histopathological lesions in visceral organs of birds challenged with the wild-type strain are more severe than in birds infected with the mutant. The mutant shows a sensitivity pattern similar to the parental strain following exposure to several hydrophobic reagents
lipid A structures of lpxM and lpxP mutants lack the secondary lauroyl 12:0 group (R3'') or palmitoleoyl 16:1 group (R2''), respectively, and thus both represent a pentaacyl lipid A. Lipid A of Yersinia pestis lpxM/lpxP double mutant lacks both secondary acyl groups, 12:0 and 16:1, and is thus represented by the tetraacyl form. The absence of at least one acyl group is crucial for binding of lipopolysaccharide to toll-like receptor TLR4. Lipopolysaccharide from lpxM and and lpxP mutants induces TNF production at approximately the same level, the former being a slightly stronger activator than the latter
2.3.1.243 acyl-Kdo2-lipid IVA acyltransferase
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