calicheamicin

naturalproductmech:mibig-06ee60b602 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REVIEWED records curator sign-off on identity, structure, filing class and producer claims; DEPRECATED retains a superseded or out-of-scope record.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	HXCHCVDVKSCDHU-IXTZGUNISA-N
SMILES	CCN[C@H]1CO[C@H](C[C@@H]1OC)O[C@@H]2[C@H]([C@@H]([C@H](OC2O[C@H]3C#C/C=C\C#C[C@]\4(CC(=O)C(=C3/C4=C\CSSSC)NC(=O)OC)O)C)NO[C@H]5C[C@@H]([C@@H]([C@H](O5)C)SC(=O)C6=C(C(=C(C(=C6OC)OC)O[C@H]7[C@@H]([C@@H]([C@H]([C@@H](O7)C)O)OC)O)I)C)O)O
Stereochemistry	undefined stereocentres — the InChIKey does not distinguish this compound from its stereoisomers
Cross-references	pubchem:6438329

Filing pathway

Polyketides — 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 pks, from MIBiG.

Producer organisms 1

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
Micromonospora echinospora NCBITaxon:1877	SOURCE_ASSERTION	mibig:BGC0000033	DOI:10.1126/science.1072105

Occurrences 0

None cited.

Biosynthetic gene clusters 1

Accession	Host	Locus evidence	Genome
mibig:BGC0000033	Micromonospora echinospora NCBITaxon:1877	CLUSTER_UNSTATED	genbank:AF497482.1

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.

Mechanism & Biosynthesis Overview

Causal graph — biosynthesis 4 nodes, 3 edges

Partial Micromonospora echinospora calicheamicin biosynthesis graph for inferred CalO3-catalyzed iodination of an orsellinic acid-derived carrier thioester.

Subject	Predicate	Object	Notes	Evidence
orsellinic acid-derived carrier thioester	is iodinated by	CalO3 flavin-dependent halogenase	MITE represents CalO3 iodination as an inferred reaction for either a CoA-bound or 4'-phosphopantetheine-bound orsellinic acid derivative; the exact carrier form is not distinguished here.	https://mite.bioinformatics.nl/repository/MITE0000005 DOI:10.1002/prot.22131 https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk https://www.uniprot.org/uniprotkb/Q8KND5 https://www.ncbi.nlm.nih.gov/protein/AAM70353.1 reference https://mite.bioinformatics.nl/repository/MITE0000005 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet Iodination of orsellenic acid derivate, assumed to be bound to coenzyme A co-factor notes MITE0000005 is active, assigns inferred CoA- and 4'-phosphopantetheine-bound orsellinic acid derivative iodination reactions to CalO3, lists flavin mononucleotide as the organic cofactor, and links CalO3 to UniProtKB:Q8KND5, GenPept AAM70353.1, and MIBiG BGC0000033. reference DOI:10.1002/prot.22131 evidence type PRIMARY_EXPERIMENT notes McCoy et al. structurally characterized the downstream CalO2 P450 and proposed that CalO3-catalyzed iodination may precede the CalO2 step on a CoA- or ACP-bound substrate; this supports the reaction placement as an inference, not a direct CalO3 assay. reference https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes MIBiG BGC0000033.5 places calO3/AAM70353.1 inside the active Micromonospora echinospora calicheamicin biosynthetic gene cluster and links the CDS to MITE0000005 at 100% identity. reference https://www.uniprot.org/uniprotkb/Q8KND5 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND5 resolves as a 420 aa Micromonospora echinospora calO3/CalO3 TrEMBL entry, cross-references EMBL AF497482 protein AAM70353.1, and carries flavin-dependent halogenase domain cross-references. reference https://www.ncbi.nlm.nih.gov/protein/AAM70353.1 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes NCBI Protein AAM70353.1 is the Micromonospora echinospora CalO3 translation encoded by calO3 at AF497482.1:73840..75102.
flavin mononucleotide	serves as organic cofactor for	CalO3 flavin-dependent halogenase	MITE lists flavin mononucleotide as CalO3's organic cofactor for the inferred iodination reaction.	https://mite.bioinformatics.nl/repository/MITE0000005 https://www.uniprot.org/uniprotkb/Q8KND5 reference https://mite.bioinformatics.nl/repository/MITE0000005 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet Iodination of orsellenic acid derivate, assumed to be bound to coenzyme A co-factor notes MITE0000005 is active, assigns inferred CoA- and 4'-phosphopantetheine-bound orsellinic acid derivative iodination reactions to CalO3, lists flavin mononucleotide as the organic cofactor, and links CalO3 to UniProtKB:Q8KND5, GenPept AAM70353.1, and MIBiG BGC0000033. reference https://www.uniprot.org/uniprotkb/Q8KND5 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND5 resolves as a 420 aa Micromonospora echinospora calO3/CalO3 TrEMBL entry, cross-references EMBL AF497482 protein AAM70353.1, and carries flavin-dependent halogenase domain cross-references.
CalO3 flavin-dependent halogenase	forms	iodinated orsellinic acid-derived carrier thioester	MITE's CalO3 reaction SMARTS add iodine to the aromatic ring of the carrier-tethered orsellinic acid derivative; both represented products remain pathway intermediates.	https://mite.bioinformatics.nl/repository/MITE0000005 DOI:10.1002/prot.22131 https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk https://www.uniprot.org/uniprotkb/Q8KND5 https://www.ncbi.nlm.nih.gov/protein/AAM70353.1 reference https://mite.bioinformatics.nl/repository/MITE0000005 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet Iodination of orsellenic acid derivate, assumed to be bound to coenzyme A co-factor notes MITE0000005 is active, assigns inferred CoA- and 4'-phosphopantetheine-bound orsellinic acid derivative iodination reactions to CalO3, lists flavin mononucleotide as the organic cofactor, and links CalO3 to UniProtKB:Q8KND5, GenPept AAM70353.1, and MIBiG BGC0000033. reference DOI:10.1002/prot.22131 evidence type PRIMARY_EXPERIMENT notes McCoy et al. structurally characterized the downstream CalO2 P450 and proposed that CalO3-catalyzed iodination may precede the CalO2 step on a CoA- or ACP-bound substrate; this supports the reaction placement as an inference, not a direct CalO3 assay. reference https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes MIBiG BGC0000033.5 places calO3/AAM70353.1 inside the active Micromonospora echinospora calicheamicin biosynthetic gene cluster and links the CDS to MITE0000005 at 100% identity. reference https://www.uniprot.org/uniprotkb/Q8KND5 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND5 resolves as a 420 aa Micromonospora echinospora calO3/CalO3 TrEMBL entry, cross-references EMBL AF497482 protein AAM70353.1, and carries flavin-dependent halogenase domain cross-references. reference https://www.ncbi.nlm.nih.gov/protein/AAM70353.1 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes NCBI Protein AAM70353.1 is the Micromonospora echinospora CalO3 translation encoded by calO3 at AF497482.1:73840..75102.

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

Causal graph — biosynthesis 4 nodes, 3 edges

Partial Micromonospora echinospora calicheamicin biosynthesis graph for CalO6-catalyzed SAM-dependent C2-O-methylation of an orsellinic acid-derived carrier thioester.

Subject	Predicate	Object	Notes	Evidence
orsellinic acid-derived carrier thioester	is C2-O-methylated by	CalO6 O-methyltransferase	MITE represents CalO6 O-methylation for either a CoA-bound or 4'-phosphopantetheine-bound orsellinic acid derivative; the exact carrier form is not distinguished here.	DOI:10.1002/cbic.201402119 https://mite.bioinformatics.nl/repository/MITE0000006 https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk https://www.uniprot.org/uniprotkb/Q8KND2 https://www.ncbi.nlm.nih.gov/protein/AAM70356.1 reference DOI:10.1002/cbic.201402119 evidence type PRIMARY_EXPERIMENT notes Singh et al. functionally characterized CalO6 as the calicheamicin orsellinate C2-O-methyltransferase and supported a CoA- or ACP-bound substrate for the O-methylation reaction. reference https://mite.bioinformatics.nl/repository/MITE0000006 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet O-methylation of orsellenic acid, assumed to be bound to coenzyme A cofactor notes MITE0000006 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound orsellinic acid O-methylation reactions to CalO6, lists SAM as an organic cofactor, and links CalO6 to UniProtKB:Q8KND2, GenPept AAM70356.1, and MIBiG BGC0000033. reference https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes MIBiG BGC0000033.5 places calO6/AAM70356.1 inside the active Micromonospora echinospora calicheamicin biosynthetic gene cluster and links the CDS to MITE0000006 at 100% identity. reference https://www.uniprot.org/uniprotkb/Q8KND2 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND2 resolves as a 356 aa Micromonospora echinospora calO6/CalO6 TrEMBL entry, cross-references EMBL AF497482 protein AAM70356.1 and PDB 4Z2Y, and carries SAM-dependent methyltransferase domain cross-references. reference https://www.ncbi.nlm.nih.gov/protein/AAM70356.1 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes NCBI Protein AAM70356.1 is the Micromonospora echinospora CalO6 translation encoded by calO6 at AF497482.1:80077..81147.
S-adenosyl-L-methionine	supplies a methyl group to	CalO6 O-methyltransferase	MITE lists SAM as CalO6's organic cofactor for this O-methylation reaction.	DOI:10.1002/cbic.201402119 https://mite.bioinformatics.nl/repository/MITE0000006 https://www.uniprot.org/uniprotkb/Q8KND2 reference DOI:10.1002/cbic.201402119 evidence type PRIMARY_EXPERIMENT notes Singh et al. functionally characterized CalO6 as the calicheamicin orsellinate C2-O-methyltransferase and supported a CoA- or ACP-bound substrate for the O-methylation reaction. reference https://mite.bioinformatics.nl/repository/MITE0000006 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet O-methylation of orsellenic acid, assumed to be bound to coenzyme A cofactor notes MITE0000006 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound orsellinic acid O-methylation reactions to CalO6, lists SAM as an organic cofactor, and links CalO6 to UniProtKB:Q8KND2, GenPept AAM70356.1, and MIBiG BGC0000033. reference https://www.uniprot.org/uniprotkb/Q8KND2 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND2 resolves as a 356 aa Micromonospora echinospora calO6/CalO6 TrEMBL entry, cross-references EMBL AF497482 protein AAM70356.1 and PDB 4Z2Y, and carries SAM-dependent methyltransferase domain cross-references.
CalO6 O-methyltransferase	forms	C2-O-methylated orsellinic acid-derived carrier thioester	MITE's CalO6 reaction SMARTS add a methoxy group to the carrier-tethered orsellinic acid derivative; both represented products remain pathway intermediates.	DOI:10.1002/cbic.201402119 https://mite.bioinformatics.nl/repository/MITE0000006 https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk https://www.uniprot.org/uniprotkb/Q8KND2 https://www.ncbi.nlm.nih.gov/protein/AAM70356.1 reference DOI:10.1002/cbic.201402119 evidence type PRIMARY_EXPERIMENT notes Singh et al. functionally characterized CalO6 as the calicheamicin orsellinate C2-O-methyltransferase and supported a CoA- or ACP-bound substrate for the O-methylation reaction. reference https://mite.bioinformatics.nl/repository/MITE0000006 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet O-methylation of orsellenic acid, assumed to be bound to coenzyme A cofactor notes MITE0000006 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound orsellinic acid O-methylation reactions to CalO6, lists SAM as an organic cofactor, and links CalO6 to UniProtKB:Q8KND2, GenPept AAM70356.1, and MIBiG BGC0000033. reference https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes MIBiG BGC0000033.5 places calO6/AAM70356.1 inside the active Micromonospora echinospora calicheamicin biosynthetic gene cluster and links the CDS to MITE0000006 at 100% identity. reference https://www.uniprot.org/uniprotkb/Q8KND2 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND2 resolves as a 356 aa Micromonospora echinospora calO6/CalO6 TrEMBL entry, cross-references EMBL AF497482 protein AAM70356.1 and PDB 4Z2Y, and carries SAM-dependent methyltransferase domain cross-references. reference https://www.ncbi.nlm.nih.gov/protein/AAM70356.1 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes NCBI Protein AAM70356.1 is the Micromonospora echinospora CalO6 translation encoded by calO6 at AF497482.1:80077..81147.

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

Causal graph — biosynthesis 4 nodes, 3 edges

Partial Micromonospora echinospora calicheamicin biosynthesis graph for CalO1-catalyzed SAM-dependent O-methylation of an iodinated orsellinic acid-derived carrier thioester.

Subject	Predicate	Object	Notes	Evidence
iodinated orsellinic acid-derived carrier thioester	is O-methylated by	CalO1 O-methyltransferase	MITE represents CalO1 O-methylation for either a CoA-bound or 4'-phosphopantetheine-bound iodinated orsellinic acid derivative; the exact carrier form is not distinguished here.	https://mite.bioinformatics.nl/repository/MITE0000007 DOI:10.1002/cbic.201402119 DOI:10.1107/S090744491100360X https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk https://www.uniprot.org/uniprotkb/Q8KNE5 https://www.ncbi.nlm.nih.gov/protein/AAM70343.1 reference https://mite.bioinformatics.nl/repository/MITE0000007 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet O-methylation of iodinated orsellenic acid derivate, assumed to be bound to coenzyme A cofactor notes MITE0000007 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound iodinated orsellinic acid derivative O-methylation reactions to CalO1, lists SAM as an organic cofactor, links the reaction rows to DOI:10.1002/cbic.201402119, and links CalO1 to UniProtKB:Q8KNE5, GenPept AAM70343.1, and MIBiG BGC0000033. reference DOI:10.1002/cbic.201402119 evidence type PRIMARY_EXPERIMENT notes Singh et al. functionally characterized the upstream CalO6 O-methyltransferase and integrated earlier CalO1 and CalO2 structural studies into a proposed calicheamicin orsellinate tailoring sequence involving CoA- or ACP-bound substrates. reference DOI:10.1107/S090744491100360X evidence type PRIMARY_EXPERIMENT notes Chang et al. reported the CalO1 crystal structure, described CalO1 as a putative calicheamicin orsellinic acid O-methyltransferase, and observed structural determinants consistent with accommodation of an acyl-carrier-protein-bound substrate. reference https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes MIBiG BGC0000033.5 places calO1/AAM70343.1 inside the active Micromonospora echinospora calicheamicin biosynthetic gene cluster and links the CDS to MITE0000007 at 100% identity. reference https://www.uniprot.org/uniprotkb/Q8KNE5 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KNE5 resolves as a 345 aa Micromonospora echinospora calO1/CalO1 TrEMBL entry, cross-references EMBL AF497482 protein AAM70343.1 and PDB 3LST, and carries SAM-dependent methyltransferase domain cross-references. reference https://www.ncbi.nlm.nih.gov/protein/AAM70343.1 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes NCBI Protein AAM70343.1 is the Micromonospora echinospora CalO1 translation encoded by calO1 at AF497482.1:60938..61975 on the reverse strand.
S-adenosyl-L-methionine	supplies a methyl group to	CalO1 O-methyltransferase	MITE lists SAM as CalO1's organic cofactor for this O-methylation reaction.	https://mite.bioinformatics.nl/repository/MITE0000007 DOI:10.1107/S090744491100360X https://www.uniprot.org/uniprotkb/Q8KNE5 reference https://mite.bioinformatics.nl/repository/MITE0000007 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet O-methylation of iodinated orsellenic acid derivate, assumed to be bound to coenzyme A cofactor notes MITE0000007 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound iodinated orsellinic acid derivative O-methylation reactions to CalO1, lists SAM as an organic cofactor, links the reaction rows to DOI:10.1002/cbic.201402119, and links CalO1 to UniProtKB:Q8KNE5, GenPept AAM70343.1, and MIBiG BGC0000033. reference DOI:10.1107/S090744491100360X evidence type PRIMARY_EXPERIMENT notes Chang et al. reported the CalO1 crystal structure, described CalO1 as a putative calicheamicin orsellinic acid O-methyltransferase, and observed structural determinants consistent with accommodation of an acyl-carrier-protein-bound substrate. reference https://www.uniprot.org/uniprotkb/Q8KNE5 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KNE5 resolves as a 345 aa Micromonospora echinospora calO1/CalO1 TrEMBL entry, cross-references EMBL AF497482 protein AAM70343.1 and PDB 3LST, and carries SAM-dependent methyltransferase domain cross-references.
CalO1 O-methyltransferase	forms	O-methylated iodinated orsellinic acid-derived carrier thioester	MITE's CalO1 reaction SMARTS add a methoxy group to the carrier-tethered iodinated orsellinic acid derivative; both represented products remain pathway intermediates.	https://mite.bioinformatics.nl/repository/MITE0000007 DOI:10.1002/cbic.201402119 DOI:10.1107/S090744491100360X https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk https://www.uniprot.org/uniprotkb/Q8KNE5 https://www.ncbi.nlm.nih.gov/protein/AAM70343.1 reference https://mite.bioinformatics.nl/repository/MITE0000007 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet O-methylation of iodinated orsellenic acid derivate, assumed to be bound to coenzyme A cofactor notes MITE0000007 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound iodinated orsellinic acid derivative O-methylation reactions to CalO1, lists SAM as an organic cofactor, links the reaction rows to DOI:10.1002/cbic.201402119, and links CalO1 to UniProtKB:Q8KNE5, GenPept AAM70343.1, and MIBiG BGC0000033. reference DOI:10.1002/cbic.201402119 evidence type PRIMARY_EXPERIMENT notes Singh et al. functionally characterized the upstream CalO6 O-methyltransferase and integrated earlier CalO1 and CalO2 structural studies into a proposed calicheamicin orsellinate tailoring sequence involving CoA- or ACP-bound substrates. reference DOI:10.1107/S090744491100360X evidence type PRIMARY_EXPERIMENT notes Chang et al. reported the CalO1 crystal structure, described CalO1 as a putative calicheamicin orsellinic acid O-methyltransferase, and observed structural determinants consistent with accommodation of an acyl-carrier-protein-bound substrate. reference https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes MIBiG BGC0000033.5 places calO1/AAM70343.1 inside the active Micromonospora echinospora calicheamicin biosynthetic gene cluster and links the CDS to MITE0000007 at 100% identity. reference https://www.uniprot.org/uniprotkb/Q8KNE5 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KNE5 resolves as a 345 aa Micromonospora echinospora calO1/CalO1 TrEMBL entry, cross-references EMBL AF497482 protein AAM70343.1 and PDB 3LST, and carries SAM-dependent methyltransferase domain cross-references. reference https://www.ncbi.nlm.nih.gov/protein/AAM70343.1 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes NCBI Protein AAM70343.1 is the Micromonospora echinospora CalO1 translation encoded by calO1 at AF497482.1:60938..61975 on the reverse strand.

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

Causal graph — biosynthesis 4 nodes, 3 edges

Partial Micromonospora echinospora calicheamicin biosynthesis graph for CalO2-catalyzed heme-dependent hydroxylation of an iodinated orsellinic acid-derived carrier thioester.

Subject	Predicate	Object	Notes	Evidence
iodinated orsellinic acid-derived carrier thioester	is hydroxylated by	CalO2 cytochrome P450	MITE represents CalO2 hydroxylation for either a CoA-bound or 4'-phosphopantetheine-bound iodinated orsellinic acid derivative; the exact carrier form is not distinguished here.	https://mite.bioinformatics.nl/repository/MITE0000008 DOI:10.1002/prot.22131 https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk https://www.uniprot.org/uniprotkb/Q8KND6 https://www.ncbi.nlm.nih.gov/protein/AAM94799.1 reference https://mite.bioinformatics.nl/repository/MITE0000008 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet Hydroxylation of iodinated orsellenic acid derivate, assumed to be bound to coenzyme A notes MITE0000008 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound iodinated orsellinic acid derivative hydroxylation reactions to CalO2, lists heme as an organic cofactor, links the reaction rows to DOI:10.1002/prot.22131, and links CalO2 to UniProtKB:Q8KND6, GenPept AAM94799.1, and MIBiG BGC0000033. reference DOI:10.1002/prot.22131 evidence type PRIMARY_EXPERIMENT notes McCoy et al. structurally characterized heme-bound CalO2, performed ligand-binding studies with iodinated orsellinic acid thioester mimics, and proposed that the CalO2-catalyzed step may occur after CalO3-catalyzed iodination on a CoA- or ACP-bound substrate. reference https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes MIBiG BGC0000033.5 places calO2/AAM94799.1 inside the active Micromonospora echinospora calicheamicin biosynthetic gene cluster and links the CDS to MITE0000008 at 100% identity. reference https://www.uniprot.org/uniprotkb/Q8KND6 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND6 resolves as a 397 aa Micromonospora echinospora calO2/CalO2 TrEMBL entry, cross-references EMBL AF497482 protein AAM94799.1 and PDB 3BUJ, carries cytochrome P450 domain cross-references, and annotates heme b binding sites from the 3BUJ structure. reference https://www.ncbi.nlm.nih.gov/protein/AAM94799.1 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes NCBI Protein AAM94799.1 is the Micromonospora echinospora CalO2 translation encoded by calO2 at AF497482.1:72606..73799 on the forward strand.
heme b	serves as prosthetic group for	CalO2 cytochrome P450	MITE lists heme as CalO2's organic cofactor, and the CalO2 crystal structure contains heme b.	https://mite.bioinformatics.nl/repository/MITE0000008 DOI:10.1002/prot.22131 https://www.uniprot.org/uniprotkb/Q8KND6 reference https://mite.bioinformatics.nl/repository/MITE0000008 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet Hydroxylation of iodinated orsellenic acid derivate, assumed to be bound to coenzyme A notes MITE0000008 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound iodinated orsellinic acid derivative hydroxylation reactions to CalO2, lists heme as an organic cofactor, links the reaction rows to DOI:10.1002/prot.22131, and links CalO2 to UniProtKB:Q8KND6, GenPept AAM94799.1, and MIBiG BGC0000033. reference DOI:10.1002/prot.22131 evidence type PRIMARY_EXPERIMENT notes McCoy et al. structurally characterized heme-bound CalO2, performed ligand-binding studies with iodinated orsellinic acid thioester mimics, and proposed that the CalO2-catalyzed step may occur after CalO3-catalyzed iodination on a CoA- or ACP-bound substrate. reference https://www.uniprot.org/uniprotkb/Q8KND6 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND6 resolves as a 397 aa Micromonospora echinospora calO2/CalO2 TrEMBL entry, cross-references EMBL AF497482 protein AAM94799.1 and PDB 3BUJ, carries cytochrome P450 domain cross-references, and annotates heme b binding sites from the 3BUJ structure.
CalO2 cytochrome P450	forms	hydroxylated iodinated orsellinic acid-derived carrier thioester	MITE's CalO2 reaction SMARTS hydroxylate the carrier-tethered iodinated orsellinic acid derivative; both represented products remain pathway intermediates.	https://mite.bioinformatics.nl/repository/MITE0000008 DOI:10.1002/prot.22131 https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk https://www.uniprot.org/uniprotkb/Q8KND6 https://www.ncbi.nlm.nih.gov/protein/AAM94799.1 reference https://mite.bioinformatics.nl/repository/MITE0000008 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 snippet Hydroxylation of iodinated orsellenic acid derivate, assumed to be bound to coenzyme A notes MITE0000008 is active, lists an in-vitro assay evidence code, assigns CoA- and 4'-phosphopantetheine-bound iodinated orsellinic acid derivative hydroxylation reactions to CalO2, lists heme as an organic cofactor, links the reaction rows to DOI:10.1002/prot.22131, and links CalO2 to UniProtKB:Q8KND6, GenPept AAM94799.1, and MIBiG BGC0000033. reference DOI:10.1002/prot.22131 evidence type PRIMARY_EXPERIMENT notes McCoy et al. structurally characterized heme-bound CalO2, performed ligand-binding studies with iodinated orsellinic acid thioester mimics, and proposed that the CalO2-catalyzed step may occur after CalO3-catalyzed iodination on a CoA- or ACP-bound substrate. reference https://mibig.secondarymetabolites.org/repository/BGC0000033.5/BGC0000033.gbk evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes MIBiG BGC0000033.5 places calO2/AAM94799.1 inside the active Micromonospora echinospora calicheamicin biosynthetic gene cluster and links the CDS to MITE0000008 at 100% identity. reference https://www.uniprot.org/uniprotkb/Q8KND6 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes UniProtKB:Q8KND6 resolves as a 397 aa Micromonospora echinospora calO2/CalO2 TrEMBL entry, cross-references EMBL AF497482 protein AAM94799.1 and PDB 3BUJ, carries cytochrome P450 domain cross-references, and annotates heme b binding sites from the 3BUJ structure. reference https://www.ncbi.nlm.nih.gov/protein/AAM94799.1 evidence type DATABASE_ASSERTION retrieved on 2026-10-02 notes NCBI Protein AAM94799.1 is the Micromonospora echinospora CalO2 translation encoded by calO2 at AF497482.1:72606..73799 on the forward strand.

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

Explore across X-Mech

AntibioticMech (calicheamicin) ↗ MediaIngredientMech (naturalproductmech:mibig-06ee60b602) ↗ TaxonMech: Micromonospora echinospora (NCBITaxon:1877) ↗ PathwayMech (mibig:BGC0000033) ↗

Provenance

Source concept	Source	Version
BGC0000033	MIBIG	5

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