desferriexochelin 772MS
CHEBI:61152 EXACT REVIEWED
What these status tags mean
Curation status describes a workflow state. SEEDED means the record entered through the source-seeding workflow; it does not imply that no later curation occurred. PROPOSED marks an addition awaiting review; REVIEWED records curator sign-off on identity, structure, filing class and producer claims; DEPRECATED retains a superseded or out-of-scope record. These are workflow decisions, not independently verified human review. Agent-assisted contributions may appear in the record history.
Grounding describes the identifier mapping: EXACT uses an ontology identity asserted by the source; MINTED keeps a local identifier when no defensible ontology identity is available; REVIEW_NEEDED flags an exact structure whose ontology identity needs adjudication. The grounding note retains any unresolved alternatives. These tags do not establish the strength of producer or activity evidence.
A carboxylic ester-lactam secreted by Mycobacterium tuberculosis which is both lipid- and water-soluble and acts as a siderophore.
Structure
| Standard InChIKey | CICZEXPNYSZNEI-UHFFFAOYSA-N |
|---|---|
| SMILES | COC(=O)CCCCCC(=O)N(O)CCCCC(NC(=O)C1COC(c2ccccc2O)=N1)C(=O)OC(C)CC(=O)NC1CCCCN(O)C1=O |
| Stereochemistry | undefined stereocentres — the InChIKey does not distinguish this compound from its stereoisomers |
Filing pathway
Amino acids and peptides — computed by NPClassifier npclassifier.gnps2.org@2026-10-30, which is why it is pinned rather than recomputed. The gene cluster's asserted class is nrps, pks, from MIBiG.
Producer organisms 2
A claim that this taxon makes the compound. The basis says what the evidence addressed — a knockout and a database assertion are not the same claim.
| Taxon | Basis | Cluster | Evidence |
|---|---|---|---|
| Mycobacterium tuberculosis Strain: Erdman NCBITaxon:1773 |
AXENIC_CULTURE | PMID:7761471
|
|
| Mycobacterium tuberculosis H37Rv Strain: H37Rv NCBITaxon:83332 |
BGC_CHARACTERIZED | mibig:BGC0001021 | PMID:9831524
|
Occurrences 0
None cited.
Biosynthetic gene clusters 1
| Accession | Host | Locus evidence | Genome |
|---|---|---|---|
| mibig:BGC0001021 | Mycobacterium tuberculosis H37Rv NCBITaxon:83332 |
CLUSTER_DEMONSTRATED | genbank:AL123456.3 |
A locus claim and a taxon claim are different questions. Heterologous expression settles the first and leaves the second where the isolation report left it.
Biosynthesis curated
Written by a curator with claim-level evidence on each step; not derived from a source. This is what the rest of the record exists to support.
| Step | Enzyme | Reaction | Substrate → product | Evidence |
|---|---|---|---|---|
| 1 | MbtI (salicylate synthase) and MbtA (salicyl-AMP ligase) | CHEBI:17333 → CHEBI:16914 | PMID:9831524 | |
| 2 | MbtB-MbtF (NRPS-PKS), MbtG (lysine N6-monooxygenase), and MbtK (acyltransferase) | CHEBI:16914 + CHEBI:17115 + CHEBI:18019 → CHEBI:61152 | PMID:7761471 |
Step 1: Conversion of chorismic acid to salicylic acid by MbtI and ATP-dependent adenylation to salicyl-AMP by MbtA.
Step 2: Hybrid NRPS-PKS assembly of the 2-hydroxyphenyloxazoline-lysine-3-hydroxybutyrate-cyclolysine core from salicylic acid, L-serine, and L-lysine, followed by N6-hydroxylation and acylation with a methyl-esterified dicarboxylic acid chain to yield desferriexochelin 772MS.
Mechanism & Biosynthesis Overview
Causal graph — bioactivity 9 nodes, 8 edges
Hybrid NRPS-PKS biosynthesis of the extracellular salicylate-type siderophore desferriexochelin 772MS in Mycobacterium tuberculosis and hexadentate coordination of host Fe(III) and CMM cation Ga(III).
| Subject | Predicate | Object | Notes | Evidence |
|---|---|---|---|---|
| salicylic acid | substrate_of | mbtA-J biosynthetic gene cluster (BGC0001021) | Activated as salicyl-AMP by MbtA to form the N-terminal 2-hydroxyphenyloxazoline ring. | PMID:9831524
|
| L-serine | substrate_of | mbtA-J biosynthetic gene cluster (BGC0001021) | Condensed with salicylate and cyclodehydrated to form the oxazoline ring in the 772SM series. | PMID:7761471
|
| L-lysine | substrate_of | mbtA-J biosynthetic gene cluster (BGC0001021) | Provides the internal linear N6-hydroxylysine and C-terminal cyclic N6-hydroxylysine hydroxamate ligands. | PMID:7761471
|
| mbtA-J biosynthetic gene cluster (BGC0001021) | synthesizes | desferriexochelin 772MS | Synthesizes extracellular desferriexochelin 772MS. | PMID:10655517
|
| desferriexochelin 772MS | chelates | iron(3+) | Scavenges Fe(III) from host transferrin and lactoferrin via hexadentate coordination. | PMID:8666910
|
| iron(3+) | transferred_to | desferrimycobactin T | Ferriexochelin 772SM transfers chelated Fe(III) to cell-wall-associated desferrimycobactin T. | PMID:8666910
|
| desferrimycobactin T | enables | siderophore transport | Mediates iron delivery across the Mycobacterium tuberculosis cell envelope. | PMID:8666910
|
| desferriexochelin 772MS | chelates | gallium(3+) | [CMM] Coordinates trivalent gallium(3+) via the hexadentate phenolate-oxazoline-bishydroxamate core. | PMID:10992462
|
Every edge carries its own citation; an uncited edge is refused by the corpus tests.
Molecular targets 2
| Target | Target organism | Measurement | Evidence |
|---|---|---|---|
| iron(3+) OTHER BINDS Primary physiological ferric ion chelation via hexadentate 2-hydroxyphenyloxazoline + bis-hydroxamate coordination (ferriexochelin 772SM / carboxymycobactin, 1:1 complex) secreted by Mycobacterium tuberculosis to scavenge Fe(III) from host transferrin and lactoferrin and transfer it to cell-wall mycobactin T. |
PMID:7761471 |
||
| gallium(3+) OTHER BINDS [Critical Mineral & Material (CMM)] Hexadentate coordination of trivalent gallium(3+) via the 2-hydroxyphenyloxazoline and two N6-hydroxylysine hydroxamate donor groups (redox-inactive trivalent Fe(III) mimic). |
PMID:10992462 |
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Provenance
| Source concept | Source | Version |
|---|---|---|
| CHEBI:61152 | CHEBI | 3-star |
This page is generated from data/natural_products/amino_acids_and_peptides/desferriexochelin-772ms.yaml, which is generated from the committed inventories. Neither is edited by hand.