G2Q9A6 · MYCB_THET4
- ProteinDiels-Alderase mycB
- GenemycB
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids440 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score3/5
Function
function
Diels-Alderase; part of the gene cluster that mediates the biosynthesis of myceliothermophins, mycotoxins that contain a trans-fused decalin ring system connected to a conjugated 3-pyrrolin-2-one moiety and that have potential anti-tumor properties (PubMed:27960349).
The polyketide synthase module (PKS) of the PKS-NRPS mycA is responsible for the synthesis of the octaketide backbone (PubMed:27960349).
The downstream nonribosomal peptide synthetase (NRPS) module then amidates the carboxyl end of the octaketide with a leucine (PubMed:27960349).
A reductase-like domain (R) at the C-terminus catalyzes the reductive release of the polyketide-amino acid intermediate (PubMed:27960349).
Because mycA lacks a designated enoylreductase (ER) domain, the required activity is provided the enoyl reductase mycC (PubMed:27960349).
Following mycA-catalyzed construction and release of aminoacyl polyketide aldehyde, Knoevenagel condensation yields the expected ketone (PubMed:27960349).
This C18 keto acyclic precursor is the substrate of the Diels-Alderase mycB, that catalyzes the Diels-Alder cycloaddition to produce myceliothermophin E (PubMed:27960349).
A yet unknown oxygenase involved in the production of myceliothermophin A, via substitution with a hydroxyl group at the C21, has still to be identified (PubMed:27960349).
The polyketide synthase module (PKS) of the PKS-NRPS mycA is responsible for the synthesis of the octaketide backbone (PubMed:27960349).
The downstream nonribosomal peptide synthetase (NRPS) module then amidates the carboxyl end of the octaketide with a leucine (PubMed:27960349).
A reductase-like domain (R) at the C-terminus catalyzes the reductive release of the polyketide-amino acid intermediate (PubMed:27960349).
Because mycA lacks a designated enoylreductase (ER) domain, the required activity is provided the enoyl reductase mycC (PubMed:27960349).
Following mycA-catalyzed construction and release of aminoacyl polyketide aldehyde, Knoevenagel condensation yields the expected ketone (PubMed:27960349).
This C18 keto acyclic precursor is the substrate of the Diels-Alderase mycB, that catalyzes the Diels-Alder cycloaddition to produce myceliothermophin E (PubMed:27960349).
A yet unknown oxygenase involved in the production of myceliothermophin A, via substitution with a hydroxyl group at the C21, has still to be identified (PubMed:27960349).
Catalytic activity
- (5S)-5-(2-methylpropyl)-3-[(2E,6R,8E,10E,12E)-6,8,10,12-tetramethyltetradeca-2,8,10,12-tetraenoyl]-2,5-dihydro-1H-pyrrol-2-one = (5S)-3-[(1S,2R,4aR,6R,8aS)-2-(but-2-en-2-yl)-3,4a,6-trimethyl-1,2,4a,5,6,7,8,8a-octahydronaphthalene-1-carbonyl]-5-(2-methylpropyl)-2,5-dihydro-1H-pyrrol-2-oneThis reaction proceeds in the forward direction.
- (5Z)-5-(2-methylpropylidene)-3-[(2E,6R,8E,10E,12E)-6,8,10,12-tetramethyltetradeca-2,8,10,12-tetraenoyl]-2,5-dihydro-1H-pyrrol-2-one = myceliothermophin EThis reaction proceeds in the forward direction.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
75 μM | the C18 keto acyclic precursor |
Pathway
Mycotoxin biosynthesis.
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | isomerase activity |
Keywords
- Molecular function
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameDiels-Alderase mycB
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Fungi > Dikarya > Ascomycota > Pezizomycotina > Sordariomycetes > Sordariomycetidae > Sordariales > Chaetomiaceae > Thermothelomyces
Accessions
- Primary accessionG2Q9A6
Proteomes
Organism-specific databases
Phenotypes & Variants
Disruption phenotype
Completely abolishes the production of myceliothermophin E, but leads to the accumulation of its C18 keto acyclic precursor.
PTM/Processing
Features
Showing features for signal, chain, glycosylation.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-18 | |||||
Sequence: MGYLVKLACGLLLPLATA | ||||||
Chain | PRO_5003436058 | 19-440 | Diels-Alderase mycB | |||
Sequence: DVNLAQQPFGEFEWQPKFDTPSGDHTSCAVSRLSAYEVGEGPVSFSLSPTEHPEIPKLSTINSTVWEQWEFDAVSESGTGSVLMGFSRDPSYSFFGQGNLRVEFYMTLEDGTRIQELEYTESSTVIDCPDSIRGIWNSSDRSYAFEISRDMQRARVWWDTGREKGSIAIESTTTPHLADGEIWPPEEGESRVKKSWPSVKLSPGLYMSQPIAGGKVTAHVQIGKKTMSITGYGAHSRLWAENSWFKICRGWQIMRGFLGPYTISYWRPLSRLDDWVPYFAAHLFKHGRLVFTSQVGAPSQQVDYTQFHSDFSGNVSGSLADKATGRVLEFVSPSTGKTWRFHHRHFAKMFEMGFGGGRGLTGFLDEIVGGEVGTDEEFTGRGFSEQVLLPDEIKQWQIWVVYGIGFLGRWKNTVTNLVLSIW | ||||||
Glycosylation | 80 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Glycosylation | 155 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Glycosylation | 332 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N |
Keywords
- PTM
PTM databases
Structure
Family & Domains
Sequence similarities
Belongs to the Diels-Alderase family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length440
- Mass (Da)49,347
- Last updated2011-11-16 v1
- Checksum5DC67D6456AD0FB3
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
CP003003 EMBL· GenBank· DDBJ | AEO57198.1 EMBL· GenBank· DDBJ | Genomic DNA |