PMID:8478319

Citation	Chen, L and Coleman, WG Jr (1993) Cloning and characterization of the Escherichia coli K-12 rfa-2 (rfaC) gene, a gene required for lipopolysaccharide inner core synthesis. J. Bacteriol. 175:2534-40
Abstract	A genetically defined mutation, designated rfa-2, results in altered lipopolysaccharide (LPS) biosynthesis. rfa-2 mutants produce a core-defective LPS that contains lipid A and a single sugar moiety, 2-keto-3-deoxyoctulosonic acid, in the LPS core region. Such LPS core-defective or deep-rough (R) mutant structures were previously designated chemotype Re. Phenotypically, rfa-2 mutants exhibit increased permeability to a number of hydrophilic and hydrophobic agents. By restriction analyses and complementation studies, we clearly defined the rfa-2 gene on a 1,056-bp AluI-DraI fragment. The rfa-2 gene and the flanking rfa locus regions were completely sequenced. Additionally, the location of the rfa-2 gene on the physical map of the Escherichia coli chromosome was determined. The rfa-2 gene encodes a 36,000-dalton polypeptide in an in vivo expression system. N-terminal analysis of the purified rfa-2 gene product confirmed the first 24 amino acid residues as deduced from the nucleotide sequence of the rfa-2 gene coding region. By interspecies complementation, a Salmonella typhimurium rfaC mutant (LPS chemotype Re) is transformed with the E. coli rfa-2+ gene, and the transformant is characterized by wild-type sensitivity to novobiocin (i.e., uninhibited growth at 600 micrograms of novobiocin per ml) and restoration of the ability to synthesize wild-type LPS structures. On the basis of the identity and significant similarity of the rfa-2 gene sequence and its product to the recently defined (D. M. Sirisena, K. A. Brozek, P. R. MacLachlan, K. E. Sanderson, and C. R. H. Raetz, J. Biol. Chem. 267:18874-18884, 1992), the S. typhimurium rfaC gene sequence and its product (heptosyltransferase 1), the E. coli K-12 rfa-2 locus will be designated rfaC.
Links	PubMed PMC204554
Keywords	Amino Acid Sequence; Bacterial Proteins; Base Sequence; Chromosome Mapping; Cloning, Molecular; Escherichia coli/genetics; Genes, Bacterial/genetics; Genetic Complementation Test; Glycosyltransferases; Lipopolysaccharides/chemistry; Lipopolysaccharides/metabolism; Molecular Sequence Data; Restriction Mapping; Salmonella typhimurium/genetics; Sequence Analysis; Sequence Homology, Amino Acid; Transformation, Genetic
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
ECOLI:RFAC		GO:0009244: lipopolysaccharide core region biosynthetic process	ECO:0000315:		P		Figure 4a - LPS profile of strains by SDS-PAGE. Mutant phenotype of rfa-2 mutant strain (lane 3) was restored to wildtype by complementing with an rfa-2 plasmid (lane 1).	complete CACAO 4649
ECOLI:RFAC	involved_in	GO:0009244: lipopolysaccharide core region biosynthetic process	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete

References

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