arg6 (SPBC725.14, UniProt O94330) notes

Identity and naming

• PomBase arg6 = mitochondrial N-acetylglutamate synthase (NAGS, EC 2.3.1.1), ortholog of S. cerevisiae ARG2 (P40360). [UniProt:O94330 "RecName: Full=Amino-acid acetyltransferase, mitochondrial;"]
• Naming trap: S. cerevisiae ARG6 is part of the ARG5,6 kinase/reductase polyprotein (S. pombe arg11), not NAGS.
• PANTHER PTHR23342:SF4 "AMINO-ACID ACETYLTRANSFERASE, MITOCHONDRIAL"; InterPro IPR011190 (fungal NAGS) and IPR006855 (vertebrate-like GNAT). Predicted transit peptide 1..19. [UniProt:O94330]

Function

• Catalysis: [UniProt:O94330 "Reaction=L-glutamate + acetyl-CoA = N-acetyl-L-glutamate + CoA + H(+);"] — by similarity only; no S. pombe enzyme assay in the cached literature.
• Pathway: first step of the acetylated ornithine route [UniProt:O94330 "N-acetylglutamate synthase involved in arginine biosynthesis."]
• Genetic: PomBase EXP annotation to arginine biosynthesis from PMID:17248775 (1977 genetic mapping paper, abstract only; the abstract does not name arg6, presumably the arg6 auxotrophic marker is mapped in the full text); also PomBase EXP from the deletion-library arginine-auxotroph screen PMID:32896087

Location

• Mitochondrion by ORFeome YFP screen [UniProt:O94330 "SUBCELLULAR LOCATION: Mitochondrion {ECO:0000269|PubMed:16823372}."]; PomBase GO-CAM 6690711d00000916 places arg6 NAGS in mitochondrial matrix, causally upstream of arg11 acetylglutamate kinase.

Curation points

• GO:0097054 L-glutamate biosynthetic process (NAS, keyword mapping GO_REF:0000051) is wrong in direction: NAGS consumes glutamate. Remove.
• Core MF GO:0004042, BP GO:0006526 (and GO:0006592 ornithine biosynthesis, IBA), CC mitochondrial matrix — same as yeast ARG2 review.
• Yeast ARG2 is in the NAGS/NAGK complex (GO:0106098) with Arg5,6; no S. pombe evidence for arg6–arg11 complex in cached literature, so in_complex not asserted.

2026-10-26 systematic fungal annotation audit

Reviewed all 11 existing rows and the core functions with the review and annotation-reviewer workflows. Preserved every machine-sourced term, evidence code, qualifier, source identifier, WITH/FROM entry and row order. No new annotations were added in this audit.

The NAGS assignment combines fungal architecture, phylogenetic inference and native arginine auxotrophy. No purified target assay was established in the consulted sources. A pathway keyword does not turn glutamate consumption into glutamate biosynthesis; that directionally incompatible NAS claim remains removed.

Normal publication caching completed. Normal Falcon research with Perplexity-lite fallback was attempted for this gene; authentication/quota failures prevented a generated report. Manual review used the actual cached primary sources and curated UniProt, and no provider-named research file was fabricated. Per-gene attempts and validation logs are in .cache/module-audit-logs/arginine-SCHPO-arg6-*. Abstract-only or bibliographic-only sources are distinguished from full text in reference reviews; unavailable source details are not treated as experimental refutations.

Actions: ACCEPT 8, MODIFY 2, REMOVE 1. Record sections were backfilled; focused schema/reference validation passed on the initial complete panel. Final targeted checks and HTML rendering are recorded in the audit logs.

PR #5563 follow-up, 2026-10-26

Restored supported GO:0005739 mitochondrion rows to ACCEPT under the explicit root-organelle policy; existing matrix rows remain separate. Reasons distinguish organelle screens, direct targeting, publication-linked curated evidence and unavailable full text. No original annotation payload changed. Cytosol decisions use target-specific fractionation/processing evidence rather than relationship qualifiers or generic precursor transit. For Aga1, matrix inference does not imply universal post-import autoproteolysis.