Reaction: ATP + a lipid-linked O antigen[cytosol] + H2O = ADP + phosphate + a lipid-linked O antigen[periplasm]
Other name(s): wzm (gene name); wzt (gene name)
Systematic name: ATP phosphohydrolase (ABC-type, homopolymeric O-antigen exporting)
Comments: Unlike heteropolymeric O antigens, which are polymerized in the periplasm by EC 2.4.99.27, O antigen polymerase Wzy, homopolymeric O antigens are polymerized inside the cytoplasm by a progressive transfer of sugar monomers to a growing chain attached to a polyprenyl diphosphate membrane anchor. When the chain reaches its full length it is transported across the cytoplasmic membrane by this ABC-type transporter, which consists of an ATP-binding subunit (Wzt) and an integral membrane protein (Wzm). Wzm proteins are poorly conserved in their primary sequence. Once in the periplasm, the O antigen is ligated to the lipid A-core complex by EC 2.4.99.26, O-antigen ligase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9028-04-0
References:
1. Kido, N., Torgov, V.I., Sugiyama, T., Uchiya, K., Sugihara, H., Komatsu, T., Kato, N. and Jann, K. Expression of the O9 polysaccharide of Escherichia coli: sequencing of the E. coli O9 rfb gene cluster, characterization of mannosyl transferases, and evidence for an ATP-binding cassette transport system. J. Bacteriol. 177 (1995) 2178-2187. [PMID: 7536735]
2. Rocchetta, H.L. and Lam, J.S. Identification and functional characterization of an ABC transport system involved in polysaccharide export of A-band lipopolysaccharide in Pseudomonas aeruginosa. J. Bacteriol. 179 (1997) 4713-4724. [PMID: 9244257]
3. Cuthbertson, L., Powers, J. and Whitfield, C. The C-terminal domain of the nucleotide-binding domain protein Wzt determines substrate specificity in the ATP-binding cassette transporter for the lipopolysaccharide O-antigens in Escherichia coli serotypes O8 and O9a. J. Biol. Chem. 280 (2005) 30310-30319. [PMID: 15980069]
4. Cuthbertson, L., Kimber, M.S. and Whitfield, C. Substrate binding by a bacterial ABC transporter involved in polysaccharide export. Proc. Natl. Acad. Sci. USA 104 (2007) 19529-19534. [PMID: 18032609]
5. Mann, E., Mallette, E., Clarke, B.R., Kimber, M.S. and Whitfield, C. The Klebsiella pneumoniae O12 ATP-binding cassette (ABC) transporter recognizes the terminal residue of its O-antigen polysaccharide substrate. J. Biol. Chem. 291 (2016) 9748-9761. [PMID: 26934919]
6. Mann, E., Kelly, S.D., Al-Abdul-Wahid, M.S., Clarke, B.R., Ovchinnikova, O.G., Liu, B. and Whitfield, C. Substrate recognition by a carbohydrate-binding module in the prototypical ABC transporter for lipopolysaccharide O-antigen from Escherichia coli O9a. J. Biol. Chem. 294 (2019) 14978-14990. [PMID: 31416837]