streptozotocin

naturalproductmech:mibig-34dab48dce MINTED SEEDED

Grounding review: No 3-star ChEBI entry shares this structure, so the record keeps a content-hashed identifier.

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REVIEWED records curator sign-off on identity, structure, filing class and producer claims; DEPRECATED retains a superseded or out-of-scope record.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.

Structure

Standard InChIKey	ZSJLQEPLLKMAKR-YDEIVXIUSA-N
SMILES	CN(N=O)C(=O)N[C@H]1C(O)O[C@H](CO)[C@@H](O)[C@@H]1O
Stereochemistry	undefined stereocentres — the InChIKey does not distinguish this compound from its stereoisomers
Cross-references	npatlas:NPA032744

Filing pathway

Carbohydrates — computed by NPClassifier npclassifier.gnps2.org@2026-09-07, which is why it is pinned rather than recomputed. The gene cluster's asserted class is other, 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
Streptomyces achromogenes subsp. streptozoticus NCBITaxon:285532	BGC_CHARACTERIZED	mibig:BGC0002313	PMID:30728519
Streptomyces achromogenes subsp. streptozoticus NCBITaxon:285532	SOURCE_ASSERTION	mibig:BGC0002294	DOI:10.3390/ijms13055751

Occurrences 1

Somebody found the compound in this organism and cited it. That is not a claim that the organism makes it, and nothing here promotes one to the other.

Taxon	Source	Reference
Streptomyces achromogenes NCBITaxon:67255	LOTUS	DOI:10.1021/JA00994A053

Biosynthetic gene clusters 2

Accession	Host	Locus evidence	Genome
mibig:BGC0002313	Streptomyces achromogenes subsp. streptozoticus NCBITaxon:285532	CLUSTER_DEMONSTRATED	genbank:MK303572.1
mibig:BGC0002294	Streptomyces achromogenes subsp. streptozoticus NCBITaxon:285532	CLUSTER_DEMONSTRATED	genbank:MK440296.1

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	SznE UniProtKB:A0A411EW25	RHEA:59756	CHEBI:32682 → CHEBI:114953	DOI:10.1021/jacs.8b13049
2	SznF UniProtKB:A0A411MR89	RHEA:69052	CHEBI:114953 → CHEBI:143209	DOI:10.1038/s41586-019-0894-z

Step 1: This curates only the Streptomyces achromogenes subsp. streptozoticus NRRL 2697 SznE N-methyltransferase step from the BGC0002313/MK303572.1 route; RHEA:59756 also uses S-adenosyl-L-methionine and releases S-adenosyl-L-homocysteine and a proton.

Step 2: This curates SznF's overall oxidative rearrangement from N(omega)-methyl-L-arginine to the unstable N-nitrosourea intermediate in the BGC0002313/MK303572.1 route; downstream attachment to the sugar scaffold remains uncurated.

Mechanism & Biosynthesis Overview

Causal graph — biosynthesis 5 nodes, 4 edges

Partial Streptomyces achromogenes subsp. streptozoticus streptozotocin biosynthesis graph for the SznE and SznF reactions that form the N-nitrosourea precursor from L-arginine.

Subject	Predicate	Object	Notes	Evidence
L-argininium(1+)	is methylated by	SznE	RHEA:59756 uses S-adenosyl-L-methionine as the methyl donor.	DOI:10.1021/jacs.8b13049 https://www.uniprot.org/uniprotkb/A0A411EW25 https://www.ncbi.nlm.nih.gov/protein/QBA82201.1 https://www.ncbi.nlm.nih.gov/protein/QBA82041.1 reference DOI:10.1021/jacs.8b13049 evidence type PRIMARY_EXPERIMENT snippet free l-arginine is N-methylated by StzE to give Nω-monomethyl-l-arginine notes He et al. identified the streptozocin N-nitrosourea precursor pathway and biochemically demonstrated the SznE/StzE arginine N-methyltransferase reaction. reference https://www.uniprot.org/uniprotkb/A0A411EW25 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes Reviewed UniProtKB:A0A411EW25 is Streptomyces achromogenes subsp. streptozoticus SznE, gene sznE, cross-references EMBL MK303572 protein QBA82201.1 and EMBL MK291259 protein QBA82041.1, and annotates RHEA:59756 with ChEBI participants CHEBI:15378, CHEBI:32682, CHEBI:57856, CHEBI:59789, and CHEBI:114953. reference https://www.ncbi.nlm.nih.gov/protein/QBA82201.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept QBA82201.1 is the MK303572.1 sznE coding sequence from the Streptomyces achromogenes subsp. streptozoticus BGC0002313 locus and is sequence-identical to UniProtKB:A0A411EW25. reference https://www.ncbi.nlm.nih.gov/protein/QBA82041.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept QBA82041.1 is the MK291259.1 standalone sznE coding sequence deposited with the primary SznF study and is sequence-identical to BGC0002313 QBA82201.1 and UniProtKB:A0A411EW25.
SznE	forms	(2S)-2-ammonio-5-{[iminio(methylamino)methyl]amino}pentanoate	N(omega)-methyl-L-arginine is the SznF substrate in the streptozotocin N-nitrosourea precursor pathway.	DOI:10.1021/jacs.8b13049 https://www.uniprot.org/uniprotkb/A0A411EW25 https://www.ncbi.nlm.nih.gov/protein/QBA82201.1 https://www.ncbi.nlm.nih.gov/protein/QBA82041.1 reference DOI:10.1021/jacs.8b13049 evidence type PRIMARY_EXPERIMENT snippet free l-arginine is N-methylated by StzE to give Nω-monomethyl-l-arginine notes He et al. identified the streptozocin N-nitrosourea precursor pathway and biochemically demonstrated the SznE/StzE arginine N-methyltransferase reaction. reference https://www.uniprot.org/uniprotkb/A0A411EW25 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes Reviewed UniProtKB:A0A411EW25 is Streptomyces achromogenes subsp. streptozoticus SznE, gene sznE, cross-references EMBL MK303572 protein QBA82201.1 and EMBL MK291259 protein QBA82041.1, and annotates RHEA:59756 with ChEBI participants CHEBI:15378, CHEBI:32682, CHEBI:57856, CHEBI:59789, and CHEBI:114953. reference https://www.ncbi.nlm.nih.gov/protein/QBA82201.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept QBA82201.1 is the MK303572.1 sznE coding sequence from the Streptomyces achromogenes subsp. streptozoticus BGC0002313 locus and is sequence-identical to UniProtKB:A0A411EW25. reference https://www.ncbi.nlm.nih.gov/protein/QBA82041.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept QBA82041.1 is the MK291259.1 standalone sznE coding sequence deposited with the primary SznF study and is sequence-identical to BGC0002313 QBA82201.1 and UniProtKB:A0A411EW25.
(2S)-2-ammonio-5-{[iminio(methylamino)methyl]amino}pentanoate	is oxidatively rearranged by	SznF	RHEA:69052 abstracts SznF's iron-dependent overall reaction from N(omega)-methyl-L-arginine to the N-nitrosourea intermediate.	DOI:10.1038/s41586-019-0894-z https://www.uniprot.org/uniprotkb/A0A411MR89 https://www.ncbi.nlm.nih.gov/protein/QBA82202.1 https://www.ncbi.nlm.nih.gov/protein/QBA82042.1 reference DOI:10.1038/s41586-019-0894-z evidence type PRIMARY_EXPERIMENT snippet catalyses an oxidative rearrangement of the guanidine group of Nω-methyl-L-arginine to generate an N-nitrosourea product notes Ng et al. biochemically and structurally characterized Streptomyces achromogenes subsp. streptozoticus SznF as the N-nitrosating metalloenzyme in streptozotocin biosynthesis. reference https://www.uniprot.org/uniprotkb/A0A411MR89 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes Reviewed UniProtKB:A0A411MR89 is Streptomyces achromogenes subsp. streptozoticus SznF, gene sznF, cross-references EMBL MK303572 protein QBA82202.1 and EMBL MK291260 protein QBA82042.1, and annotates overall RHEA:69052 plus SznF's successive RHEA:69056, RHEA:69060, RHEA:69064, and RHEA:69068 partial reactions. reference https://www.ncbi.nlm.nih.gov/protein/QBA82202.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept QBA82202.1 is the MK303572.1 sznF coding sequence from the Streptomyces achromogenes subsp. streptozoticus BGC0002313 locus and is sequence-identical to UniProtKB:A0A411MR89. reference https://www.ncbi.nlm.nih.gov/protein/QBA82042.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept QBA82042.1 is the MK291260.1 standalone sznF coding sequence deposited with the primary SznF study and is sequence-identical to BGC0002313 QBA82202.1 and UniProtKB:A0A411MR89.
SznF	forms	N(delta)-hydroxy-N(omega)-methyl-N(omega)-nitroso-L-citrulline zwitterion	The product node is the RHEA:69052 N(delta)-hydroxy-N(omega)-methyl-N(omega)-nitroso-L-citrulline product rather than the final streptozotocin scaffold.	DOI:10.1038/s41586-019-0894-z https://www.uniprot.org/uniprotkb/A0A411MR89 https://www.ncbi.nlm.nih.gov/protein/QBA82202.1 https://www.ncbi.nlm.nih.gov/protein/QBA82042.1 reference DOI:10.1038/s41586-019-0894-z evidence type PRIMARY_EXPERIMENT snippet catalyses an oxidative rearrangement of the guanidine group of Nω-methyl-L-arginine to generate an N-nitrosourea product notes Ng et al. biochemically and structurally characterized Streptomyces achromogenes subsp. streptozoticus SznF as the N-nitrosating metalloenzyme in streptozotocin biosynthesis. reference https://www.uniprot.org/uniprotkb/A0A411MR89 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes Reviewed UniProtKB:A0A411MR89 is Streptomyces achromogenes subsp. streptozoticus SznF, gene sznF, cross-references EMBL MK303572 protein QBA82202.1 and EMBL MK291260 protein QBA82042.1, and annotates overall RHEA:69052 plus SznF's successive RHEA:69056, RHEA:69060, RHEA:69064, and RHEA:69068 partial reactions. reference https://www.ncbi.nlm.nih.gov/protein/QBA82202.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept QBA82202.1 is the MK303572.1 sznF coding sequence from the Streptomyces achromogenes subsp. streptozoticus BGC0002313 locus and is sequence-identical to UniProtKB:A0A411MR89. reference https://www.ncbi.nlm.nih.gov/protein/QBA82042.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept QBA82042.1 is the MK291260.1 standalone sznF coding sequence deposited with the primary SznF study and is sequence-identical to BGC0002313 QBA82202.1 and UniProtKB:A0A411MR89.

Every edge carries its own citation; an uncited edge is refused by the corpus tests.

Explore across X-Mech

AntibioticMech (streptozotocin) ↗ MediaIngredientMech (naturalproductmech:mibig-34dab48dce) ↗ TaxonMech: Streptomyces achromogenes subsp. streptozoticus (NCBITaxon:285532) ↗ TaxonMech: Streptomyces achromogenes subsp. streptozoticus (NCBITaxon:285532) ↗ PathwayMech (mibig:BGC0002313) ↗ PathwayMech (mibig:BGC0002294) ↗

Open questions 1

shared-structure — This structure is reported by more than one MIBiG entry: BGC0002294, BGC0002313. Confirm they describe the same compound rather than an upstream cross-reference error.

Provenance

Source concept	Source	Version
BGC0002313	MIBIG	3
BGC0002294	MIBIG	3

This page is generated from data/natural_products/carbohydrates/streptozotocin.yaml, which is generated from the committed inventories. Neither is edited by hand.