IUBMB Enzyme Nomenclature


Accepted name: ABC-type lipopolysaccharide transporter

Reaction: ATP + H2O + lipopolysaccharide[side 1] = ADP + phosphate + lipopolysaccharide[side 2]

Other name(s): lptB (gene name); lipopolysaccharide transport system; lipopolysaccharide-transporting ATPase

Systematic name: ATP phosphohydrolase (ABC-type, lipopolysaccharide-exporting)

Comments: An ATP-binding cassette (ABC) type transporter, characterized by the presence of two similar ATP-binding domains/proteins and two integral membrane domains/proteins. Does not undergo phosphorylation during the transport process. The enzyme, characterized from the bacterium Escherichia coli, functions as part of the lipopolysaccharide (LPS) export system, a seven protein system that translocates LPS from the inner- to the outer membrane. The ATPase activity in this system is implicated in releasing LPS from the inner membrane.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Sperandeo, P., Cescutti, R., Villa, R., Di Benedetto, C., Candia, D., Deho, G. and Polissi, A. Characterization of lptA and lptB, two essential genes implicated in lipopolysaccharide transport to the outer membrane of Escherichia coli. J. Bacteriol. 189 (2007) 244-253. [PMID: 17056748]

2. Ruiz, N., Gronenberg, L.S., Kahne, D. and Silhavy, T.J. Identification of two inner-membrane proteins required for the transport of lipopolysaccharide to the outer membrane of Escherichia coli. Proc. Natl Acad. Sci. USA 105 (2008) 5537-5542. [PMID: 18375759]

3. Narita, S. and Tokuda, H. Biochemical characterization of an ABC transporter LptBFGC complex required for the outer membrane sorting of lipopolysaccharides. FEBS Lett. 583 (2009) 2160-2164. [PMID: 19500581]

4. Tran, A.X., Dong, C. and Whitfield, C. Structure and functional analysis of LptC, a conserved membrane protein involved in the lipopolysaccharide export pathway in Escherichia coli. J. Biol. Chem 285 (2010) 33529-33539. [PMID: 20720015]

5. Okuda, S., Freinkman, E. and Kahne, D. Cytoplasmic ATP hydrolysis powers transport of lipopolysaccharide across the periplasm in E. coli. Science 338 (2012) 1214-1217. [PMID: 23138981]

6. Chng, S.S., Gronenberg, L.S. and Kahne, D. Proteins required for lipopolysaccharide assembly in Escherichia coli form a transenvelope complex. Biochemistry 49 (2010) 4565-4567. [PMID: 20446753]

[EC created 2000 as EC, transferred 2018 to EC]

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