CaltechAUTHORS
Published October 30, 2014 | Version Supplemental Material
Journal Article Open

Covalently linked hopanoid-lipid A improves outer-membrane resistance of a Bradyrhizobium symbiont of legumes

Creators

  • 1. ROR icon University of Naples Federico II
  • 2. ROR icon Centre de Coopération Internationale en Recherche Agronomique pour le Développement
  • 3. ROR icon The University of Texas at Arlington
  • 4. ROR icon California Institute of Technology
  • 5. ROR icon Research Center Borstel - Leibniz-Center for Medicine and Biosciences
  • 6. ROR icon Jeonbuk National University

Abstract

Lipopolysaccharides (LPSs) are major components of the outer membrane of Gram-negative bacteria and are essential for their growth and survival. They act as a structural barrier and play an important role in the interaction with eukaryotic hosts. Here we demonstrate that a photosynthetic Bradyrhizobium strain, symbiont of Aeschynomene legumes, synthesizes a unique LPS bearing a hopanoid covalently attached to lipid A. Biophysical analyses of reconstituted liposomes indicate that this hopanoid-lipid A structure reinforces the stability and rigidity of the outer membrane. In addition, the bacterium produces other hopanoid molecules not linked to LPS. A hopanoid-deficient strain, lacking a squalene hopene cyclase, displays increased sensitivity to stressful conditions and reduced ability to survive intracellularly in the host plant. This unusual combination of hopanoid and LPS molecules may represent an adaptation to optimize bacterial survival in both free-living and symbiotic states.

Additional Information

© 2014 Macmillan Publishers Limited. Received 17 Mar 2014; Accepted 29 Aug 2014; Published 30 Oct 2014. This work was supported by grants from the French national research agency (ANR-SESAM-2010-BLAN-170801 and ANR-BugsInaCell-13-BSV7-0013-02) from the Italian Ministry of Education, Universities and Research (PRIN 2009J98Z3_001, PRIN 2010 BJ23MN_007, PRIN 2011 L9SH3K and FIRB-MERIT RBNE08HWLZ), from Mizutani Foundation for Glycoscience 2014 and from grants from NASA (NNX12AD93G) and the Howard Hughes Medical Institute. D.K.N. is an HHMI Investigator. We thank J.F. Arrighi (IRD, France), A. Verméglio (CEA, Cadarache France), P. Mergaert and O. Pierre (ISV, CNRS, Gif-sur-Yvette, France), A. Imberty (Cermav, France) and T. Chrzanowski (UTA, Arlington, TX, USA) for criticisms and corrections of the manuscript.

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Additional details

Identifiers

Eprint ID
52465
DOI
10.1038/ncomms6106
Resolver ID
CaltechAUTHORS:20141208-104816963

Funding

Agence Nationale pour la Recherche (ANR)
ANR-SESAM-2010-BLAN-170801
Agence Nationale pour la Recherche (ANR)
ANR-BugsInaCell-13-BSV7-0013-02
Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR)
PRIN 2009J98Z3_001
Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR)
PRIN 2010 BJ23MN_007
Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR)
PRIN 2011 L9SH3K
Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR)
FIRB-MERIT RBNE08HWLZ
Mizutani Foundation for Glycoscience 2014
NASA
NNX12AD93G
Howard Hughes Medical Institute (HHMI)

Dates

Created
2014-12-09
Created from EPrint's datestamp field
Updated
2023-09-26
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Division of Geological and Planetary Sciences (GPS)