Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Automatic assignment of GO terms using logical inference, based on on inter-ontology links
Membrane topology mapping of the O-antigen flippase (Wzx), polymerase (Wzy), and ligase (WaaL) from Pseudomonas aeruginosa PAO1 reveals novel domain architectures.
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PhoA-LacZ truncation fusions and GFP fusions map Wzx as an integral inner-membrane protein with cytoplasmic and periplasmic loops.
"Protein orientation in the inner membrane was confirmed via C-terminal fusion to green fluorescent protein."
A cationic lumen in the Wzx flippase mediates anionic O-antigen subunit translocation in Pseudomonas aeruginosa PAO1.
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Residues in TMS2 and TMS8 lining a cationic lumen are needed for Wzx flippase function.
"Construction of a tertiary structure homology model for Wzx indicated that TMS2 and TMS8 line a central cationic lumen."
Proton-dependent gating and proton uptake by Wzx support O-antigen-subunit antiport across the bacterial inner membrane.
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Purified, reconstituted Wzx mediates electrogenic, pH-modulated anion flux and proton uptake, supporting a H+-coupled antiport mechanism.
"WzxPa was capable of mediating anion flux, consistent with its cationic interior."
An O-antigen processing function for Wzx (RfbX): a promising candidate for O-unit flippase.
Effect of wzx (rfbX) mutations on A-band and B-band lipopolysaccharide biosynthesis in Pseudomonas aeruginosa O5.
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Chromosomal wzx insertion mutants lose B-band LPS and show delayed A-band LPS.
"Insertion of a Gmr cassette at two separate sites within the putative wzx gene led in both cases to the loss of B-band lipopolysaccharide (LPS) O-antigen production."