Disease relevance of rfaE

• In an attempt to elucidate the genes involved in LOS biosynthesis, we have cloned the rfaE gene from NTHi 2019 by complementing a Salmonella typhimurium rfaE mutant strain with an NTHi 2019 plasmid library [1].
• The rfaE gene encoded a polypeptide of 477 amino acid residues highly homologous to the S. enterica rfaE protein (98% identity), E. coli (93% identity), Yersenia pestis (85% identity), Haemophilus influenzae (70% identity) and Helicobacter pyroli (41% identity) with a molecular weight 53 kDa [2].

High impact information on rfaE

• In extracts of rfaC-, rfaD-, or rfaE-deficient strains, no polar products were observed with ATP [3].
• The rfaE mutant synthesizes lipopolysaccharide (LPS) lacking heptose, and the rfaE gene is postulated to be involved in ADP-heptose synthesis [1].
• Retransformation with the plasmid containing 4 kb of NTHi DNA isolated from a reconstituted mutant into rfaE mutants gave wild-type LPS phenotypes [1].
• Primer extension analysis of the rfaE gene revealed a single transcription start site at 37 bp upstream of the predicted translation start site [1].
• Mutations which resulted in the truncation of the residues following 3-deoxy-D-manno-octulosonic acid, such as the rfaE and rfaD mutations, decreased the transfer frequency to undetectable levels [4].

Chemical compound and disease context of rfaE

• The author's group has recently reported the cloning of the rfaE gene of Salmonella typhimurium, previously implicated in biosynthesis of the lipopolysaccharide (LPS)-inner core [Jin et al. (2001); Kim (2002)] [5].

Biological context of rfaE

• Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis confirmed the conversion of the rfaE mutant LPS to a wild-type LPS phenotype [1].
• The chromosomal region carrying this gene was isolated by screening a genomic library of S. typhimurium using the complementation of S. typhimurium rfaE mutant [2].
• The rfaE (WaaE) gene of Salmonella typhimurium is known to be located at 76min on the genetic map outside of the rfa gene cluster encoding core oligosaccharide biosynthesis of lipopolysaccharide(LPS) [2].

Anatomical context of rfaE

• In vitro infection experiments showed that complementation with rfaE permitted invasion of human Chang epithelial cells, larynx epidermal carcinoma HEp-2 cells and intestinal epithelial Henle-407 cells [5].

Associations of rfaE with chemical compounds

• The rfaE mutant synthesizes heptose-deficient LPS; its LPS consists of only lipid A and 3-deoxy-D-manno-octulosonic acid (KDO), and the rfaE gene is believed to be involved in the formation of ADP-L-glycero-D-manno-heptose [2].
• The product of the rfaE gene is involved in ADP-L-glycero-D-manno-heptose biosynthesis. rfaE mutants synthesize heptose-deficient LPS (Re-LPS) consisting only of lipid A and 3-deoxy-D-manno-octulosonic acid (KDO) [5].

Analytical, diagnostic and therapeutic context of rfaE

• Molecular cloning and functional expression of the rfaE gene required for lipopolysaccharide biosynthesis in Salmonella typhimurium [2].

References