Caulobacter lipid A is conditionally dispensable in the absence of fur and in the presence of anionic sphingolipids.

Journal Article (Journal Article)

Lipid A, the membrane-anchored portion of lipopolysaccharide (LPS), is an essential component of the outer membrane (OM) of nearly all Gram-negative bacteria. Here we identify regulatory and structural factors that together render lipid A nonessential in Caulobacter crescentus. Mutations in the ferric uptake regulator fur allow Caulobacter to survive in the absence of either LpxC, which catalyzes an early step of lipid A synthesis, or CtpA, a tyrosine phosphatase homolog we find is needed for wild-type lipid A structure and abundance. Alterations in Fur-regulated processes, rather than iron status per se, underlie the ability to survive when lipid A synthesis is blocked. Fitness of lipid A-deficient Caulobacter requires an anionic sphingolipid, ceramide phosphoglycerate (CPG), which also mediates sensitivity to the antibiotic colistin. Our results demonstrate that, in an altered regulatory landscape, anionic sphingolipids can support the integrity of a lipid A-deficient OM.

Full Text

Duke Authors

Cited Authors

  • Zik, JJ; Yoon, SH; Guan, Z; Stankeviciute Skidmore, G; Gudoor, RR; Davies, KM; Deutschbauer, AM; Goodlett, DR; Klein, EA; Ryan, KR

Published Date

  • May 31, 2022

Published In

Volume / Issue

  • 39 / 9

Start / End Page

  • 110888 -

PubMed ID

  • 35649364

Electronic International Standard Serial Number (EISSN)

  • 2211-1247

Digital Object Identifier (DOI)

  • 10.1016/j.celrep.2022.110888


  • eng

Conference Location

  • United States