WbpA (PA3159) is the NAD+-dependent UDP-N-acetyl-D-glucosamine 6-dehydrogenase of Pseudomonas aeruginosa serotype O5. It oxidises UDP-GlcNAc to UDP-N-acetyl-D-glucosaminuronic acid, the first of five steps (WbpA, WbpB, WbpE, WbpD, WbpI) that make UDP-2,3-diacetamido-2,3-dideoxy-D-mannuronic acid for the B-band O antigen of lipopolysaccharide. The purified enzyme needs NH4+ or K+, shows positive cooperativity for UDP-GlcNAc and is an oligomer in solution. wbpA knockouts lack B-band O antigen. It belongs to the UDP-glucose/GDP-mannose dehydrogenase family.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000271 polysaccharide biosynthetic process | IBA GO_REF:0000033 | TOO GENERAL | Summary: IBA from PTN000146785, seeded by E. coli WecC (ECA biosynthesis, IMP) and this gene's own rows (expected self-appearance). Sound at the node. Reason: True, but entailed by the accepted GO:0009243 O antigen biosynthetic process. |
| GO:0000271 polysaccharide biosynthetic process | IDA PMID:15226302 Biochemical characterization of WbpA, a UDP-N-acetyl-D-gluco... | TOO GENERAL | Summary: PseudoCAP seed row for PTN000146785. Purified WbpA makes UDP-GlcNAcA, the first O-antigen precursor. Seed verdict SOUND. Reason: True, but entailed by the accepted GO:0009243. |
| GO:0000271 polysaccharide biosynthetic process | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO from the UDP-ManNAc/GlcNAc dehydrogenase family. Reason: Entailed by the accepted GO:0009243. |
| GO:0003954 NADH dehydrogenase activity | EXP PMID:18621892 Biosynthesis of a rare di-N-acetylated sugar in the lipopoly... | REMOVE | Summary: PseudoCAP seed row for PTN000890018. NADH dehydrogenase activity is NADH oxidation; WbpA reduces NAD+ to NADH while oxidising UDP-GlcNAc. In the cited paper WbpA is only knocked out and complemented; the assayed dehydrogenases are the B. pertussis WbpO enzymes. Seed verdict WRONG. Reason: Wrong activity, in the wrong direction. The correct activity, GO:0047004, is already annotated from PMID:15226302. Supporting Evidence: PMID:15226302 the data revealed that WbpA is a UDP-N-acetyl-D-glucosamine 6-dehydrogenase (EC 1.1.1.136), which uses NAD(+) as a coenzyme PMID:18621892 Capillary electrophoresis was used to characterize the enzymatic activities of purified WbpO(1629) and WbpO(3150) |
| GO:0009243 O antigen biosynthetic process | EXP PMID:18621892 Biosynthesis of a rare di-N-acetylated sugar in the lipopoly... | ACCEPT | Summary: PseudoCAP seed row for PTN000146785. The wbpA knockout lacks B-band O antigen and His-WbpA restores it. Seed verdict SOUND. Reason: WbpA catalyses the first step to the B-band sugar precursor; core process (mutant evidence, IMP would be the usual code). Supporting Evidence: PMID:18621892 The wbpA knockout of P. aeruginosa PAO1 is devoid of B-band O antigen but still produces A-band O antigen in a variety of lengths. |
| GO:0009243 O antigen biosynthetic process | IEA GO_REF:0000041 | ACCEPT | Summary: UniPathway mapping to LPS O-antigen biosynthesis. Reason: Consistent with the experimental row. Supporting Evidence: PMID:18621892 The wbpA knockout of P. aeruginosa PAO1 is devoid of B-band O antigen but still produces A-band O antigen in a variety of lengths. |
| GO:0016020 membrane | IEA GO_REF:0000044 | REMOVE | Summary: UniProt subcellular-location mapping from a predicted transmembrane helix (residues 13-32, ECO:0000255). That segment holds the GxGxxG dinucleotide-binding motif (G22-L-G-Y-V-G27) that opens the Rossmann fold of the UDP-glucose/GDP-mannose dehydrogenase family. Reason: The prediction mistakes the NAD-binding beta-alpha-beta unit for a membrane helix. WbpA was purified and characterised as a soluble oligomer, and family members are cytoplasmic enzymes. Supporting Evidence: file:PSEAE/wbpA/wbpA-uniprot.txt TRANSMEM 13..32 |
| GO:0016491 oxidoreductase activity | IBA GO_REF:0000033 | TOO GENERAL | Summary: IBA from PTN000890018, seeded by E. coli WecC (IDA) and this gene's own rows. One of the two WbpA seed rows (GO:0003954) is wrong, but the node term stands on WecC and on the sound GO:0047004 seed. Reason: True, but entailed by the accepted GO:0047004. |
| GO:0016616 oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor | IEA GO_REF:0000120 | TOO GENERAL | Summary: Combined IEA from the UDP-glucose/GDP-mannose dehydrogenase domains. Reason: Correct class, but entailed by the accepted GO:0047004 (is_a GO:0016616). |
| GO:0016628 oxidoreductase activity, acting on the CH-CH group of donors, NAD or NADP as acceptor | IEA GO_REF:0000002 | REMOVE | Summary: InterPro2GO from IPR028359 (UDP-ManNAc/GlcNAc dehydrogenase). Reason: Wrong sub-class. UDP-GlcNAc and UDP-ManNAc 6-dehydrogenases oxidise the C6 alcohol (EC 1.1.1.136, CH-OH donors); no member acts on a CH-CH group. Supporting Evidence: PMID:15226302 the data revealed that WbpA is a UDP-N-acetyl-D-glucosamine 6-dehydrogenase (EC 1.1.1.136), which uses NAD(+) as a coenzyme |
| GO:0047004 UDP-N-acetylglucosamine 6-dehydrogenase activity | EXP PMID:15226302 Biochemical characterization of WbpA, a UDP-N-acetyl-D-gluco... | ACCEPT | Summary: PseudoCAP seed row for PTN000890018. Purified WbpA converts UDP-GlcNAc to UDP-GlcNAcA with NAD+. Seed verdict SOUND. Reason: Core molecular function, from a direct assay on purified enzyme. Supporting Evidence: PMID:15226302 the data revealed that WbpA is a UDP-N-acetyl-D-glucosamine 6-dehydrogenase (EC 1.1.1.136), which uses NAD(+) as a coenzyme |
| GO:0047004 UDP-N-acetylglucosamine 6-dehydrogenase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA from the curated EC/Rhea reaction. Reason: Consistent with the experimental row. Supporting Evidence: PMID:15226302 the data revealed that WbpA is a UDP-N-acetyl-D-glucosamine 6-dehydrogenase (EC 1.1.1.136), which uses NAD(+) as a coenzyme |
| GO:0051287 NAD binding | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: InterPro2GO from the NAD-binding domains. Reason: NAD+ is the coenzyme; true, but part of the dehydrogenase activity. Supporting Evidence: PMID:15226302 the data revealed that WbpA is a UDP-N-acetyl-D-glucosamine 6-dehydrogenase (EC 1.1.1.136), which uses NAD(+) as a coenzyme |
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