id: A8Y5A1
gene_symbol: Gfat1
taxon:
  id: NCBITaxon:7227
  label: Drosophila melanogaster
status: COMPLETE
description: 'The ProtNLM2 API snapshot retrieved 2026-09-08 contains no GO-term predictions for A8Y5A1,
  the native 434-residue Gfat1-PF product. Omission of the complete glutamine-dependent amidotransferase
  activity (GO:0004360) is not a supported deficiency: this exact product lacks the catalytic cysteine
  and most of the glutaminase module needed for that reaction. The retained SIS domains and ligand-bound
  structures of homologous human isomerase domains support carbohydrate derivative binding (GO:0097367)
  as a broad, qualified omission candidate, not proof of target-specific binding or catalysis. Participation
  in UDP-N-acetylglucosamine biosynthesis remains unresolved for this isoform. The separate FUNCTION claim
  of the complete glutamine-dependent reaction is NPI because of the missing catalytic architecture. This
  completed record assesses the absence of GO output; predictions is empty because no GO or EC prediction
  was emitted. The narrative judgment remains in the linked function review and is not a score assigned
  to the omission.'
source_documents:
- genes/DROME/Gfat1/Gfat1-protnlm-source.json
- projects/PROTNLM_EVALUATION/fly-benchmark/manifest.json
- genes/DROME/Gfat1/Gfat1-protnlm-function-review.md
- genes/DROME/Gfat1/Gfat1-uniprot.txt
- genes/DROME/Gfat1/Gfat1-bioinformatics/RESULTS.md
- publications/PMID_19059404.md
references:
- id: file:DROME/Gfat1/Gfat1-bioinformatics/RESULTS.md
  title: Gfat1 exact-isoform sequence comparison
  findings:
  - statement: The target lacks most of the glutaminase domain, including its catalytic cysteine.
    supporting_text: Only 40 of 299 residues of the annotated glutamine-amidotransferase domain remain,
      and its N-terminal catalytic Cys2 is absent.
  - statement: Both SIS domains are retained in the short product.
    supporting_text: Both SIS domains are fully retained (reference 372–512 and 543–684).
- id: PMID:19059404
  title: Structural analysis of human glutamine:fructose-6-phosphate amidotransferase, a key regulator
    in type 2 diabetes.
  findings:
  - statement: Structures of the isolated human isomerase domain demonstrate sugar-phosphate binding,
      supporting a qualified domain-level binding inference.
    supporting_text: 'We now report the first structures of the isomerase domain of the

      human GFAT in the presence of cyclic glucose-6-phosphate and linear

      glucosamine-6-phosphate.'
  full_text_unavailable: true
predictions: []