NaA622_candidate_IFRH_0 is an alternate A622-like oxidoreductase paralog in Nicotiana attenuata. Current evidence makes it a live comparison candidate for the A622/NaGR step, but the paper-backed mechanistic assignment is stronger for the primary NaA622 mapping than for this alternate accession.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
|
GO:0016491
oxidoreductase activity
|
IEA
GO_REF:0000002 |
ACCEPT |
Summary: Generic oxidoreductase activity is acceptable for this A622-like paralog, but it does not resolve whether IFRH_0 is the true late nicotine-pathway copy.
Reason: The accession clearly belongs to the oxidoreductase-like A622 family, even though its exact pathway placement relative to the primary A622 mapping is still unresolved.
Supporting Evidence:
file:NICAT/NaA622_candidate_IFRH_0/NaA622_candidate_IFRH_0-notes.md
The full preprint makes A622/NaGR one of the mechanistically resolved enzymes in nicotine synthesis, so IFRH_0 remains an A622-like paralog that has to be compared explicitly against the primary A622 mapping rather than dropped as noise.
|
Q: Does IFRH_0 have measurable nicotinic acid N-glucoside reductase activity, or is that chemistry restricted to the primary A622 mapping?
Q: Are IFRH_0 and IFRH_2 differentially expressed across root cell types or induction conditions relevant to nicotine production?
Experiment: Test recombinant IFRH_0 for NaGR-like activity using nicotinic acid N-glucoside as substrate and compare directly with the primary A622 accession.
Hypothesis: IFRH_0 has weaker or no NaGR activity relative to the primary A622 mapping.
Type: biochemical enzyme assay
Experiment: Quantify root expression and metabolite consequences after selective disruption of IFRH_0 versus the primary A622 paralog.
Hypothesis: IFRH_0 contributes less to late nicotine flux than the primary NaA622 mapping.
Type: comparative genetics plus metabolite profiling
The gene NaA622_candidate_IFRH_0 in Nicotiana attenuata (UniProt Accession: A0A1J6I5H4) encodes a protein annotated as an isoflavone reductase-like (IRL) enzyme. This classification is based on the presence of specific protein domains, including the NAD(P)-binding domain (IPR036291), NmrA-like domain (IPR008030), NmrA-type/Isoflavone reductase superfamily domain (IPR050608), and PCBER-like domain (IPR045312).
Functional Annotation and Enzymatic Activity
Isoflavone reductase-like proteins are part of the larger family of oxidoreductases, enzymes that catalyze oxidation-reduction reactions. While the specific substrate and reaction catalyzed by NaA622_candidate_IFRH_0 in N. attenuata have not been experimentally determined, the presence of these conserved domains suggests a role in redox processes, potentially involving the reduction of isoflavones or related compounds.
Biological Processes and Localization
In plants, isoflavone reductase-like proteins have been implicated in various biological processes, including defense responses against pathogens and environmental stresses. Their activity is often associated with the biosynthesis of secondary metabolites that contribute to the plant's defense mechanisms. The subcellular localization of these proteins can vary; however, they are commonly found in the cytoplasm, where they participate in metabolic pathways.
Pathway Involvement
Given the potential function of NaA622_candidate_IFRH_0 as an oxidoreductase, it may be involved in secondary metabolite biosynthesis pathways, particularly those leading to the production of phenolic compounds. These compounds play crucial roles in plant defense and adaptation to environmental challenges.
Inference from Homologous Proteins
While direct studies on NaA622_candidate_IFRH_0 are lacking, research on homologous proteins in related species provides insights into its possible functions. For instance, in Nicotiana tabacum (common tobacco), the isoflavone reductase homolog A622 has been studied for its role in plant defense mechanisms. Although the exact functions may differ, these homologous proteins often share similar roles in plant physiology.
Conclusion
In summary, NaA622_candidate_IFRH_0 in Nicotiana attenuata is predicted to function as an isoflavone reductase-like enzyme, potentially involved in redox reactions related to secondary metabolite biosynthesis and plant defense. Further experimental studies are necessary to elucidate its specific substrates, enzymatic activities, and roles within the plant's metabolic pathways.
id: A0A1J6I5H4
gene_symbol: NaA622_candidate_IFRH_0
product_type: PROTEIN
status: DRAFT
aliases:
- IFRH_0
- NaA622
taxon:
id: NCBITaxon:49451
label: Nicotiana attenuata
description: >-
NaA622_candidate_IFRH_0 is an alternate A622-like oxidoreductase paralog in
Nicotiana attenuata. Current evidence makes it a live comparison candidate for
the A622/NaGR step, but the paper-backed mechanistic assignment is stronger for
the primary NaA622 mapping than for this alternate accession.
references:
- id: GO_REF:0000002
title: Gene Ontology annotation through association of InterPro records with GO terms
findings: []
- id: file:NICAT/NaA622_candidate_IFRH_0/NaA622_candidate_IFRH_0-uniprot.txt
title: UniProt entry A0A1J6I5H4 for the alternate A622-like candidate
findings:
- statement: UniProt identifies A0A1J6I5H4 as an isoflavone reductase-like protein
supporting_text: 'DE SubName: Full=Isoflavone reductase -like a622 ;'
reference_section_type: DATABASE_ENTRY
- id: file:NICAT/NaA622_candidate_IFRH_0/NaA622_candidate_IFRH_0-notes.md
title: NaA622 alternate paralog notes
findings:
- statement: IFRH_0 remains a legitimate A622-like comparison paralog
supporting_text: The full preprint makes A622/NaGR one of the mechanistically resolved enzymes in nicotine synthesis, so IFRH_0 remains an A622-like paralog that has to be compared explicitly against the primary A622 mapping rather than dropped as noise.
reference_section_type: LITERATURE_REVIEW
- statement: Exact NICAT paralog assignment is still unresolved for the alternate A622-like copy
supporting_text: Because the paper is strongest for pathway role and weaker for exact NICAT accession resolution, IFRH_0 remains a live alternate A622-like candidate until the paralog split is settled directly.
reference_section_type: LITERATURE_REVIEW
existing_annotations:
- term:
id: GO:0016491
label: oxidoreductase activity
evidence_type: IEA
original_reference_id: GO_REF:0000002
review:
summary: >-
Generic oxidoreductase activity is acceptable for this A622-like paralog,
but it does not resolve whether IFRH_0 is the true late nicotine-pathway
copy.
action: ACCEPT
reason: >-
The accession clearly belongs to the oxidoreductase-like A622 family, even
though its exact pathway placement relative to the primary A622 mapping is
still unresolved.
supported_by:
- reference_id: file:NICAT/NaA622_candidate_IFRH_0/NaA622_candidate_IFRH_0-notes.md
supporting_text: The full preprint makes A622/NaGR one of the mechanistically resolved enzymes in nicotine synthesis, so IFRH_0 remains an A622-like paralog that has to be compared explicitly against the primary A622 mapping rather than dropped as noise.
reference_section_type: LITERATURE_REVIEW
core_functions:
- molecular_function:
id: GO:0016491
label: oxidoreductase activity
description: >-
IFRH_0 is an alternate A622-like oxidoreductase paralog that should be
compared directly against the primary NaA622 mapping for late nicotine-pathway
reductase activity.
supported_by:
- reference_id: file:NICAT/NaA622_candidate_IFRH_0/NaA622_candidate_IFRH_0-notes.md
supporting_text: Because the paper is strongest for pathway role and weaker for exact NICAT accession resolution, IFRH_0 remains a live alternate A622-like candidate until the paralog split is settled directly.
reference_section_type: LITERATURE_REVIEW
proposed_new_terms: []
suggested_questions:
- question: Does IFRH_0 have measurable nicotinic acid N-glucoside reductase activity, or is that chemistry restricted to the primary A622 mapping?
- question: Are IFRH_0 and IFRH_2 differentially expressed across root cell types or induction conditions relevant to nicotine production?
suggested_experiments:
- description: Test recombinant IFRH_0 for NaGR-like activity using nicotinic acid N-glucoside as substrate and compare directly with the primary A622 accession.
experiment_type: biochemical enzyme assay
hypothesis: IFRH_0 has weaker or no NaGR activity relative to the primary A622 mapping.
- description: Quantify root expression and metabolite consequences after selective disruption of IFRH_0 versus the primary A622 paralog.
experiment_type: comparative genetics plus metabolite profiling
hypothesis: IFRH_0 contributes less to late nicotine flux than the primary NaA622 mapping.