Reaction: ADP-L-glycero-β-D-manno-heptose + an α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] = ADP + an α-Hep-(1→3)-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A]
Glossary: Lipid A is a lipid component of the lipopolysaccharides (LPS) of Gram-negative bacteria. It consists of two glucosamine units connected by a β(1→6) bond and decorated with four to seven acyl chains and up to two phosphate groups.
Hep = L-glycero-D-manno-heptose
Other name(s): HepII; rfaF (gene name); WaaF; heptosyltransferase II
Systematic name: ADP-L-glycero-β-D-manno-heptose:an α-L-glycero-D-manno-heptosyl-(1→5)-[α-Kdo-(2→4)]-α -Kdo-(2→6)-[lipid A] 3-α-heptosyltransferase
Comments: The enzyme catalyses a glycosylation step in the biosynthesis of the inner core oligosaccharide of the lipopolysaccharide (endotoxin) of some Gram-negative bacteria.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Allen, A.G., Isobe, T. and Maskell, D.J. Identification and cloning of waaF (rfaF) from Bordetella pertussis and use to generate mutants of Bordetella spp. with deep rough lipopolysaccharide. J. Bacteriol. 180 (1998) 35-40. [PMID: 9422589]
2. Bauer, B.A., Lumbley, S.R. and Hansen, E.J. Characterization of a WaaF (RfaF) homolog expressed by Haemophilus ducreyi. Infect. Immun. 67 (1999) 899-907. [PMID: 9916106]
3. Gronow, S., Brabetz, W. and Brade, H. Comparative functional characterization in vitro of heptosyltransferase I (WaaC) and II (WaaF) from Escherichia coli. Eur. J. Biochem. 267 (2000) 6602-6611. [PMID: 11054112]
4. Gronow, S., Oertelt, C., Ervela, E., Zamyatina, A., Kosma, P., Skurnik, M. and Holst, O. Characterization of the physiological substrate for lipopolysaccharide heptosyltransferases I and II. J Endotoxin Res 7 (2001) 263-270. [PMID: 11717579]
5. Oldfield, N.J., Moran, A.P., Millar, L.A., Prendergast, M.M. and Ketley, J.M. Characterization of the Campylobacter jejuni heptosyltransferase II gene, waaF, provides genetic evidence that extracellular polysaccharide is lipid A core independent. J. Bacteriol. 184 (2002) 2100-2107. [PMID: 11914340]