Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Host organism: Homo sapiens
Associated disease: tularemia [ICD11:
1B94 
, ICD11:
XN0BX 
];
infection due to Francisella tularensis [ICD11:
XN0BX 
]
The structure was elucidated in this paperNCBI PubMed ID: 17128982Publication DOI: 10.1021/bi061767sJournal NLM ID: 0370623Publisher: American Chemical Society
Correspondence: raetz

biochem.duke.edu
Institutions: Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, Department of Biochemistry and Duke NMR Spectroscopy Center and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710
Francisella tularensis subsp. novicida U112 phospholipids, extracted without hydrolysis, consist mainly of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and two lipid A species, designated A1 and A2. These lipid A species, present in a ratio of 7:1, comprise 15% of the total phospholipids, as judged by 32Pi labeling. Although lipopolysaccharide is detectable in F. tularensis subsp. novicida U112, less than 5% of the total lipid A is covalently linked to it. A1 and A2 were analyzed by electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry, gas chromatography/mass spectrometry, and NMR spectroscopy. Both compounds are disaccharides of glucosamine, acylated with primary 3-hydroxystearoyl chains at positions 2, 3, and 2' and a secondary palmitoyl residue at position 2'. Minor isobaric species and some lipid A molecules containing a 3-hydroxypalmitoyl chain in place of 3-hydroxystearate are also present. The 4'- and 3'-positions of A1 and A2 are not derivatized, and 3-deoxy-d-manno-octulosonic acid (Kdo) is not detectable. The 1-phosphate groups of both A1 and A2 are modified with an &agr;-linked galactosamine residue, as shown by NMR spectroscopy and gas chromatography/mass spectrometry. An &agr;-linked glucose moiety is attached to the 6'-position of A2. The lipid A released by mild acid hydrolysis of F. tularensis subsp. novicida lipopolysaccharide consists solely of component A1. F. tularensis subsp. novicida mutants lacking the arnT gene do not contain a galactosamine residue on their lipid A. Formation of free lipid A in F. tularensis subsp. novicida might be initiated by an unusual Kdo hydrolase present in the membranes of this organism
Lipopolysaccharide, lipid A, NMR spectroscopy, ionization mass spectrometry, mass spectrometry, Francisella tularensis
Structure type: oligomer ; 1828.23
C
94H
178N
3O
28P
Location inside paper: p.14434, fig.7B, compound A2
Compound class: lipid A
Contained glycoepitopes: IEDB_137473,IEDB_141181,IEDB_141807,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_151531,IEDB_983931,SB_192
Methods: 13C NMR, 1H NMR, NMR-2D, GC-MS, 31P NMR, ESI-MS, mild acid hydrolysis, MALDI-TOF MS, genetic methods, mild alkaline hydrolysis
Biosynthesis and genetic data: genetic data
Related record ID(s): 20015, 20433, 20434, 20435, 20436, 31256, 31257
NCBI Taxonomy refs (TaxIDs): 401614
Show glycosyltransferases
There is only one chemically distinct structure: