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Molecular cloning, characterization, and nucleotide sequence of the rfc gene, which encodes an O-antigen polymerase of Salmonella typhimurium.

ABSTRACT: The rfc gene of Salmonella typhimurium was located in a 1.75-kb HindIII fragment and restored wild-type lipopolysaccharide synthesis ability to both an older rfc point mutant and new rfc::IS10 mutants. DNA sequencing of the HindIII fragment revealed an open reading frame which could encode a protein of 407 amino acids with an Mr of 47,472 and also revealed potential translation signals. Modulator codons accounted for 12.5% of the total codon content, providing a possible explanation for the nondetectability of the protein in subcellular systems. Secondary structure analysis suggested the presence of transmembrane beta-sheet structures, implying a possible role for the protein in translocation of hydrophilic O-antigen-containing materials. Salmonella strains of groups A, B, and D1 contained rfc-homologous DNA, but strains of groups C1, C2, C3, D2, and E2 did not.

SUBMITTER: Collins LV

PROVIDER: S-EPMC207816 | biostudies-other | 1991 Apr

REPOSITORIES: biostudies-other

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Molecular cloning, characterization, and nucleotide sequence of the rfc gene, which encodes an O-antigen polymerase of Salmonella typhimurium.

Collins L V LV Hackett J J

Journal of bacteriology 19910401 8

The rfc gene of Salmonella typhimurium was located in a 1.75-kb HindIII fragment and restored wild-type lipopolysaccharide synthesis ability to both an older rfc point mutant and new rfc::IS10 mutants. DNA sequencing of the HindIII fragment revealed an open reading frame which could encode a protein of 407 amino acids with an Mr of 47,472 and also revealed potential translation signals. Modulator codons accounted for 12.5% of the total codon content, providing a possible explanation for the nond ...[more]

PMID: 1707412

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