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3.A.1.103.2
Heteropolysaccharide O-antigen exporter, Wzm/Wzt (Feng et al., 2004). The C-terminal cytoplasmic domain of Wzt (an IgG-like β-sandwich) determines the specificity of the transporter for either O8 or O9a O-PS (Cuthbertson et al., 2007). The transporter structure reveals a continuous transmembrane channel in a nucleotide-free state (Caffalette et al. 2019). Upon ATP binding, large structural changes within the nucleotide-binding and transmembrane regions push conserved hydrophobic residues at the substrate entry site towards the periplasm and provide a model for polysaccharide translocation. With ATP bound, the transporter forms a large transmembrane channel with openings toward the membrane and periplasm. The channel's periplasmic exit is sealed by detergent molecules that block solvent permeation. Molecular dynamics simulation data suggest that, in a biological membrane, lipid molecules occupy this periplasmic exit and prevent water flux in the transporter's resting state (Caffalette et al. 2019).

Accession Number:Q6E7E9
Protein Name:Wzm(M)
Length:257
Molecular Weight:29816.00
Species:Escherichia coli [562]
Number of TMSs:6
Location1 / Topology2 / Orientation3: Secreted1
Substrate Heteropolysaccharide O-antigen

Cross database links:

Pfam: PF01061   

Gene Ontology

GO:0016020 C:membrane
GO:0005524 F:ATP binding
GO:0042626 F:ATPase activity, coupled to transmembrane m...
GO:0006810 P:transport

References (1)

[1] “Synthesis of the heteropolysaccharide O antigen of Escherichia coli O52 requires an ABC transporter: structural and genetic evidence.”  Feng L.et.al.   15231783

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Predict TMSs (Predict number of transmembrane segments)
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FASTA formatted sequence
1:	MSIMSLKTLE LVWVKAKLNL KSEASINYLS YAWWIIEPVL QMAIYYLVFA YLLKQGGHDY 
61:	VPFLLTGLIP WIWFGRSVSH AQGSIIQGKY LMNQVHISKI FFPLTFILQD ALKQILVFIL 
121:	LFIFLVLYGY DYTLGLLWII PVIFVQLLLI VAFSLIVSII VPFVRDFSFV IETGLQIMMF 
181:	CSGIFFNYKS IPAMESKIFF INPMAVILSS YRDVLMYHNA PNIKLLAYVV LLSLIMISIS 
241:	LYAFKRLEFI FPRVVQK