identifier: traitmech:000163
label: pyrazinamidase activity
definition: A physiological enzyme-activity phenotype in which a cell produces active
  nicotinamidase/pyrazinamidase enzymes that hydrolyze nicotinamide and can convert
  pyrazinamide to pyrazinoic acid.
definition_source: DOI:10.1111/j.1742-4658.2007.06241.x
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
synonyms:
- synonym_text: nicotinamidase activity
  synonym_type: RELATED_SYNONYM
  source: https://iubmb.qmul.ac.uk/enzyme/EC3/5/1/19.html
- synonym_text: nicotinamidase
  synonym_type: RELATED_SYNONYM
  source: https://iubmb.qmul.ac.uk/enzyme/EC3/5/1/19.html
- synonym_text: nicotinamide amidohydrolase
  synonym_type: RELATED_SYNONYM
  source: https://iubmb.qmul.ac.uk/enzyme/EC3/5/1/19.html
- synonym_text: nicotinamidase/pyrazinamidase
  synonym_type: RELATED_SYNONYM
  source: DOI:10.1111/j.1742-4658.2007.06241.x
evidence:
- reference: https://iubmb.qmul.ac.uk/enzyme/EC3/5/1/19.html
  snippet: <b>Reaction:</b> nicotinamide + H<small><sub>2</sub></small>O = nicotinate
    + NH<small><sub>3</sub></small>
  notes: The NC-IUBMB EC 3.5.1.19 entry grounds the nicotinamide-deamidating side
    of the PncA activity with the accepted nicotinamidase reaction.
- reference: DOI:10.1111/j.1742-4658.2007.06241.x
  snippet: The nicotinamidase/pyrazinamidase (PncA) of Mycobacterium tuberculosis
    is involved in the activation of the important front-line antituberculosis drug
    pyrazinamide by converting it into the active form, pyrazinoic acid.
  notes: Zhang et al. characterized the Mycobacterium tuberculosis PncA enzyme, linking
    nicotinamidase/pyrazinamidase activity to cellular conversion of pyrazinamide
    into pyrazinoic acid.
- reference: DOI:10.1371/journal.pone.0015785
  snippet: Pyrazinamidase (PncA) activates the first-line antituberculous drug pyrazinamide
    into pyrazinoic acid.
  notes: Petrella et al. independently describe PncA as the pyrazinamidase that activates
    pyrazinamide, supporting the pyrazinamidase label for the organism-level activity.
canonical_examples:
- taxon_id: NCBITaxon:1773
  taxon_label: Mycobacterium tuberculosis
  note: Zhang et al. characterized active nicotinamidase/pyrazinamidase PncA from
    Mycobacterium tuberculosis.
  reference: DOI:10.1111/j.1742-4658.2007.06241.x
discussions:
- discussion_id: pyrazinamidase-activity-xref-gap
  prompt: Resolve an exact external ontology class for pyrazinamidase activity before
    adding a TraitRecord xref.
  kind: CURATION_TODO
  status: OPEN
  rationale: GO:0008936 nicotinamidase activity denotes the catalytic molecular function
    rather than the organism-level pyrazinamidase/nicotinamidase phenotype, so it
    is appropriate as a causal-node grounding for the source label and not as an equivalent
    TraitRecord xref.
  posed_by: codex
  posed_date: '2026-09-12'
curation_history:
- timestamp: '2026-09-12T09:07:58Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Minted pyrazinamidase activity as a URL/DOI-backed TraitRecord after a
    repository-wide duplicate review covering ignored and hidden files; METPO has
    no exact pyrazinamidase activity class yet.
  llm_assisted: true