Biosynthesis of T1 Antigen in Salmonella: Origin of d-Galactofuranose and d-Ribofuranose Residues
AUTOR(ES)
Sarvas, Matti
RESUMO
The “T1 side chain” portion of cell wall lipopolysaccharide from T1 strains of Salmonella contains d-galactofuranose and d-ribofuranose residues. Isotope labeling studies, using intact cells of mutants each blocked at either of the two different steps of d-galactose metabolism (uridine diphosphate-glucose 4-epimerase and galactose-1-P uridylyl transferase) or at phosphoglucoisomerase, led to the following conclusions. (i) d-Galactofuranose residues are synthesized from d-galactopyranose or its derivatives, rather than by a direct conversion from other hexopyranoses or their derivatives. (ii) The pyranose-to-furanose conversion does not appear to take place at the level of the free d-galactose or d-galactose 1-phosphate. This result suggests that the conversion may occur at the stage of uridine diphosphate-d-galactose. (iii) In a mutant lacking phosphoglucoisomerase, d-ribofuranose residues in T1 side chains contained 14C derived from exogenous d-fructose-U-14C, but little 3H from exogenous d-glucose-1-3H. Thus, no evidence was found for a direct pathway of aldohexose-to-ribose conversion involving a loss of one of the carbons in the C2-C6 moiety of aldohexoses. This suggests, but does not prove, that the T1 ribofuranose residues are synthesized by conventional mechanisms involving hexose monophosphate shunt and transketolase-transaldolase reactions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=248537Documentos Relacionados
- Biosynthesis of T1 Antigen in Salmonella: Biosynthesis in a Cell-Free System
- Bacteriophage Attachment to the Somatic Antigen of Salmonella: Effect of O-Specific Structures in Leaky R Mutants and S, T1 Hybrids
- T2 lipopolysaccharide antigen of Salmonella: comparison of the properties of T2 and mucoid forms.
- T2 lipopolysaccharide antigen of Salmonella: genetic determination of T2 and properties of the T2, T2,S, and T2,SR Forms.
- Glucosylation of Lipopolysaccharide in Salmonella: Mutants Negative for O Antigen Factor 1221