Substrate specificity of the pyrophosphohydrolase LpxH determines the asymmetry of Bordetella pertussis lipid A

Arenas, Jesús (Universidad de Zaragoza) ; Pupo, Elder ; de Jonge, Eline ; Pérez-Ortega, Jesús ; Schaarschmidt, Joerg ; van der Ley, Peter ; Tommassen, Jan

Resumen: Lipopolysaccharides are anchored to the outer membrane of Gram-negative bacteria by a hydrophobic moiety known as lipid A, which potently activates the host innate immune response. Lipid A of Bordetella pertussis, the causative agent of whooping cough, displays unusual structural asymmetry with respect to the length of the acyl chains at the 3 and 3′ positions, which are 3OH-C10 and 3OH-C14 chains, respectively. Both chains are attached by the acyltransferase LpxA, the first enzyme in the lipid A biosynthesis pathway, which, in B. pertussis, has limited chain length specificity. However, this only partially explains the strict asymmetry of lipid A. In attempts to modulate the endotoxicity of B. pertussis lipid A, here we expressed the gene encoding LpxA from Neisseria meningitidis, which specifically attaches 3OH-C12 chains, in B. pertussis. This expression was lethal, suggesting that one of the downstream enzymes in the lipid A biosynthesis pathway in B. pertussis cannot handle precursors with a 3OH-C12 chain. We considered that the UDP-diacylglucosamine pyrophosphohydrolase LpxH could be responsible for this defect as well as for the asymmetry of B. pertussis lipid A. Expression of meningococcal LpxH in B. pertussis indeed resulted in new symmetric lipid A species with 3OH-C10 or 3OH-C14 chains at both the 3 and 3′ positions, as revealed by MS analysis. Furthermore, co-expression of meningococcal lpxH and lpxA resulted in viable cells that incorporated 3OH-C12 chains in B. pertussis lipid A. We conclude that the asymmetry of B. pertussis lipid A is determined by the acyl chain length specificity of LpxH.

Idioma: Inglés

DOI: 10.1074/jbc.RA118.004680

Año: 2019

Publicado en: Journal of Biological Chemistry 294, 20 (2019), 7982–7989
ISSN: 0021-9258

Factor impacto JCR: 4.238 (2019)

Categ. JCR: BIOCHEMISTRY & MOLECULAR BIOLOGY rank: 87 / 297 = 0.293 (2019) - Q2 - T1

Factor impacto SCIMAGO: 2.283 - Biochemistry (Q1) - Molecular Biology (Q1) - Cell Biology (Q1)

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Sanidad Animal (Dpto. Patología Animal)