Localization of the terminal steps of O-antigen synthesis in Salmonella typhimurium

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Journal of Bacteriology; (USA)

OSTI ID:5988396

McGrath, B C; Osborn, M J ^[1]

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1. Univ. of Connecticut Health Center, Farmington (USA)

Previous immunoelectron microscopic studies have shown that both the final intermediate in O-antigen synthesis, undecaprenol-linked O polymer, and newly synthesized O-antigenic lipopolysaccharide are localized to the periplasmic face of the inner membrane. In vivo pulse-chase experiments now provide further evidence that attachment of O antigen to core lipopolysaccharide, as well as polymerization of O-specific polysaccharide chains, takes place at the periplasmic face of the membrane. Mutants doubly conditional in lipopolysaccharide synthesis (kdsA(Ts) pmi) were constructed in which synthesis of core lipopolysaccharide and O antigen are temperature sensitive and mannose dependent, respectively. Periplasmic orientation of O antigen:core lipopolysaccharide ligase was established by experiments showing rapid chase of undecaprenol-linked O polymer, previously accumulated at 42 degrees C in the absence of core synthesis, into lipopolysaccharide following resumption of core formation at 30 degrees C. In addition, chase of the monomeric O-specific tetrasaccharide unit into lipopolysaccharide was found in similar experiments in an O-polymerase-negative (rfc kdsA(Ts) pmi) mutant, suggesting that polymerization of O chains also occurs at the external face of the inner membrane.

• OSTI ID: 5988396
• Journal Information: Journal of Bacteriology; (USA), Journal Name: Journal of Bacteriology; (USA) Vol. 173:2; ISSN JOBAA; ISSN 0021-9193
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
ANTIGENS
BACTERIA
BIOCHEMISTRY
BIOLOGICAL LOCALIZATION
BIOSYNTHESIS
CARBOHYDRATES
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL REACTIONS
CHEMISTRY
ELECTROPHORESIS
ENZYMES
LIGASES
LIPIDS
LIPOPOLYSACCHARIDES
MEMBRANES
MICROORGANISMS
ORGANIC COMPOUNDS
POLYMERIZATION
POLYSACCHARIDES
SACCHARIDES
SALMONELLA
SALMONELLA TYPHIMURIUM
SYNTHESIS