galU

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0003983 UTP:glucose-1-phosphate uridylyltransferase activity	IBA GO_REF:0000033	ACCEPT	Summary: Core catalytic activity, inherited from a GalU node seeded by enzymes with direct activity assays (E. coli GalU P0AEP3 by IDA). Reason: GalU carries the TIGR01099 galU signature and the NTP_transferase domain; the E. coli orthologue has assayed UDP-glucose pyrophosphorylase activity. This is the gene's defining function. Supporting Evidence: file:PSEAE/galU/galU-uniprot.txt NCBIfam; TIGR01099; galU; 1.
GO:0003983 UTP:glucose-1-phosphate uridylyltransferase activity	IEA GO_REF:0000120	ACCEPT	Summary: Same core activity from the InterPro/EC mapping. Reason: Consistent with the IBA row and the family signature. Supporting Evidence: file:PSEAE/galU/galU-uniprot.txt InterPro; IPR005771; GalU_uridylyltTrfase_bac/arc.
GO:0005829 cytosol	IBA GO_REF:0000033	ACCEPT	Summary: Soluble enzyme without signal peptide or TM segment. Reason: Seeded by E. coli GalU, cytosolic by IDA and HDA. Nucleotide-sugar synthesis from UTP and glucose 1-phosphate is a cytoplasmic reaction. Supporting Evidence: file:PSEAE/galU/galU-uniprot.txt Pfam; PF00483; NTP_transferase; 1.
GO:0006011 UDP-alpha-D-glucose metabolic process	IEA GO_REF:0000002	MODIFY	Summary: Correct but general; GalU makes UDP-glucose. Reason: The enzyme produces UDP-alpha-D-glucose, so the precise process is UDP-alpha-D-glucose biosynthetic process (GO:0120530), an is_a child of this term. Proposed replacements: UDP-alpha-D-glucose biosynthetic process Supporting Evidence: file:PSEAE/galU/galU-uniprot.txt Reaction=alpha-D-glucose 1-phosphate + UTP + H(+) = UDP-alpha-D-glucose + diphosphate
GO:0009244 lipopolysaccharide core region biosynthetic process	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: Right for P. aeruginosa GalU, which supplies the glucosyl donor for the LPS core, but the PTN000501197 node that propagates it also covers Gram-positive and LPS-less bacteria. Reason: On this leaf the term is supported by the PseudoCAP IMP (truncated core in galU mutants of four serogroups), and Q9I291 in its own WITH/FROM marks that seed, which is expected. GalU supplies UDP-glucose for the core glucosyltransferases rather than assembling the core itself, so the process is kept as non-core, consistent with the IMP row. The node term is a separate matter. PTN000501197 has 33 leaves, including Bacillus subtilis GtaB and YngB, Staphylococcus GtaB, Listeria lmo1078, Streptococcus, Clostridium, Mycoplasma, Streptomyces and Mycobacterium GalU orthologues, none of which make lipopolysaccharide. Both seeds (E. coli and P. aeruginosa GalU) are Gram-negative, and the E. coli seed is coded acts_upstream_of_or_within. The LPS process is a lineage-specific use of UDP-glucose, not a property of the clade (see the GO_CENTRAL defect). Propagation Review Root cause: PROPAGATION BAD Failure modes: LINEAGE OR TAXON MISMATCH Sources checked: UniProtKB:Q9I291 · galU (self; PseudoCAP IMP PMID:12044687) SUPPORTS TRANSFER Sound for P. aeruginosa; galU mutants make a truncated LPS core. UniProtKB:P0AEP3 · E. coli GalU SUPPORTS SOURCE BUT NOT TARGET EcoCyc IMP coded acts_upstream_of_or_within (PMID:10398745); right for E. coli but says nothing about Gram-positive members. PANTHER:PTN000501197 · PTN000501197 SUPPORTS SOURCE BUT NOT TARGET GalU/GtaB clade spanning Proteobacteria, Firmicutes, Mollicutes and Actinobacteria; LPS core synthesis exists only in the Gram-negative part. Supporting Evidence: PMID:12044687 Construction of galU mutants in P. aeruginosa serogroups O11, O5, O6 and O17 strains led to truncation of the LPS core, indicating the involvement of GalU in P. aeruginosa LPS core synthesis.
GO:0009244 lipopolysaccharide core region biosynthetic process	IMP PMID:12044687 Pseudomonas aeruginosa galU is required for a complete lipop...	KEEP AS NON CORE	Summary: Dean and Goldberg 2002 - galU complemented a truncated-core PA103 mutant, and galU knockouts in four serogroups truncated the LPS core. Reason: Sound genetic evidence, with complementation, that GalU is needed for a complete LPS core; the biochemical basis is clear (GalU makes the UDP-glucose donor used by the core glucosyltransferases). GalU performs the precursor step rather than core assembly, and its product also feeds other pathways, so the process is kept as non-core and the core function is the UDP-glucose pyrophosphorylase activity. Abstract only. Supporting Evidence: PMID:12044687 When the wild-type galU gene was introduced into strain PA103 wbpM-C containing the cloned wbpM gene, both LPS defects were corrected. PMID:12044687 Construction of galU mutants in P. aeruginosa serogroups O11, O5, O6 and O17 strains led to truncation of the LPS core, indicating the involvement of GalU in P. aeruginosa LPS core synthesis.