ISSN:
1432-072X
Keywords:
Rhizobium trifolii
;
Lipopolysaccharide
;
Lipid A-structure
;
“Nod” plasmids
;
3-Hydroxy fatty acids
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Structural studies have been performed on lipid A preparations derived from lipopolysaccharides of nodulating (nod+) Rhizobium trifolii wild type strains and non-nodulating (nod-) mutants deprived of the medium size “Nod” plasmid. All preparations contain a lipid A backbone composed of a β1,6-linked d-glucosamine disaccharide (GlcN II-β1,6-GlcN I) which is bis-phosphorylated at positions 1 and 4′. The phosphate group at position 4′ (GlcN II) is nonstoichiometrically substituted probably by a neutral glycosyl residue. Another substituent (probably also a neutral sugar) substitutes partly position 4 (GlcN I) of the disaccharide. The hydroxyl groups at positions 3 and 3′ are likely to be esterified by fatty acyl residue. In lipid A of nod+ strains, 3-hydroxyhexa- and octadecanoic acid are linked to the amino group of GlcN I, and 3-hydroxyhexa- and tetradecanoic acid to the amino group of GlcN II. In lipid A of nod- strains, mainly 3-hydroxyhexadecanoic acid is linked to the amino group of GlcN I, and 3-hydroxytetra- and hexadecanoic acid to that of GlcN II. The results show that rhizobial lipid A expresses many similarities to the lipid A of Enterobacteria. The structure shows, however, also peculiarities, especially regarding substituents of the lipid A backbone.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00428838
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