A0A2I1C3W7 · NSRE_ASPN1
- ProteinDecarboxylase nsrE
- GenensrE
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids151 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score2/5
Function
function
Decarboxylase; part of the gene cluster that mediates the biosynthesis of the tetrahydroxanthone dimer neosartorin, which exhibits antibacterial activity (PubMed:30394754, PubMed:32105084, PubMed:33891392).
The two different monomeric units appear to be synthesized by the same set of enzymes, among which the Baeyer-Villiger monooxygenase nsrF is the key enzyme for the divergence of the biosynthetic routes (PubMed:32105084).
The pathway begins with the synthesis of atrochrysone thioester by the polyketide synthase nsrB (PubMed:32105084).
The atrochrysone carboxyl ACP thioesterase nsrC then breaks the thioester bond and releases the atrochrysone carboxylic acid from AacuL (PubMed:32105084).
Atrochrysone carboxylic acid is decarboxylated by the decarboxylase nsrE, and oxidized by the anthrone oxygenase nsrD to yield emodin (PubMed:32105084).
Emodin is then reduced to emodin hydroquinone by the oxidoreductase nsrR (PubMed:32105084).
A-ring reduction by the short chain dehydrogenase nsrJ, dehydration by the scytalone dehydratase-like protein nsrI and probable spontaneous re-oxidation, results in overall deoxygenation to chrysophanol (PubMed:32105084).
The Baeyer-Villiger monooxygenase nsrF accepts chrysophanol as a substrate to insert one oxygen atom at two different positions to yield the precursors of both monomric units (PubMed:30394754, PubMed:32105084, PubMed:33891392).
NsrF is promiscuous/flexible in interacting with the 2 (non methylated and methylated) aromatic rings of chrysophanol, thus diverging the biosynthetic pathway at this point (PubMed:30394754, PubMed:32105084, PubMed:33891392).
After the hydrolysis of the lactones, methylesterification by the methyltransferase nsrG yields respectively moniliphenone and 2,2',6'-trihydroxy-4-methyl-6-methoxya-cyldiphenylmethanone (PubMed:30394754, PubMed:32105084).
The next steps are the hydroxylation by the FAD-dependent monooxygenase nsrK, followed by isomerization by the monooxygenase nsrQ (PubMed:32105084).
The short chain dehydrogenase/reductase nsrO then catalyzes the C-5 ketoreduction to give the xanthone skeleton of blennolide C and 5-acetylblennolide A (PubMed:32105084).
The acetyltransferase nsrL has a strict substrate specificity and uses only blennolide A but not blennolide C to yield 5-acetylblennolide A as the single-acetylated product (PubMed:30394754).
In the final step of the biosynthesis, the heterodimerization of the 2 xanthones, blennolide C and 5-acetylblennolide A, is catalyzed by the cytochrome P450 monooxygenase nsrP (PubMed:30394754).
NsrP can utilize at least three different xanthones as its substrates to perform the dimerization reaction (PubMed:30394754).
The two different monomeric units appear to be synthesized by the same set of enzymes, among which the Baeyer-Villiger monooxygenase nsrF is the key enzyme for the divergence of the biosynthetic routes (PubMed:32105084).
The pathway begins with the synthesis of atrochrysone thioester by the polyketide synthase nsrB (PubMed:32105084).
The atrochrysone carboxyl ACP thioesterase nsrC then breaks the thioester bond and releases the atrochrysone carboxylic acid from AacuL (PubMed:32105084).
Atrochrysone carboxylic acid is decarboxylated by the decarboxylase nsrE, and oxidized by the anthrone oxygenase nsrD to yield emodin (PubMed:32105084).
Emodin is then reduced to emodin hydroquinone by the oxidoreductase nsrR (PubMed:32105084).
A-ring reduction by the short chain dehydrogenase nsrJ, dehydration by the scytalone dehydratase-like protein nsrI and probable spontaneous re-oxidation, results in overall deoxygenation to chrysophanol (PubMed:32105084).
The Baeyer-Villiger monooxygenase nsrF accepts chrysophanol as a substrate to insert one oxygen atom at two different positions to yield the precursors of both monomric units (PubMed:30394754, PubMed:32105084, PubMed:33891392).
NsrF is promiscuous/flexible in interacting with the 2 (non methylated and methylated) aromatic rings of chrysophanol, thus diverging the biosynthetic pathway at this point (PubMed:30394754, PubMed:32105084, PubMed:33891392).
After the hydrolysis of the lactones, methylesterification by the methyltransferase nsrG yields respectively moniliphenone and 2,2',6'-trihydroxy-4-methyl-6-methoxya-cyldiphenylmethanone (PubMed:30394754, PubMed:32105084).
The next steps are the hydroxylation by the FAD-dependent monooxygenase nsrK, followed by isomerization by the monooxygenase nsrQ (PubMed:32105084).
The short chain dehydrogenase/reductase nsrO then catalyzes the C-5 ketoreduction to give the xanthone skeleton of blennolide C and 5-acetylblennolide A (PubMed:32105084).
The acetyltransferase nsrL has a strict substrate specificity and uses only blennolide A but not blennolide C to yield 5-acetylblennolide A as the single-acetylated product (PubMed:30394754).
In the final step of the biosynthesis, the heterodimerization of the 2 xanthones, blennolide C and 5-acetylblennolide A, is catalyzed by the cytochrome P450 monooxygenase nsrP (PubMed:30394754).
NsrP can utilize at least three different xanthones as its substrates to perform the dimerization reaction (PubMed:30394754).
Catalytic activity
- atrochrysone carboxylate + H+ = atrochrysone + CO2This reaction proceeds in the forward direction.
Pathway
Secondary metabolite biosynthesis.
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | lyase activity | |
Molecular Function | oxidoreductase activity |
Keywords
- Molecular function
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameDecarboxylase nsrE
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Fungi > Dikarya > Ascomycota > Pezizomycotina > Eurotiomycetes > Eurotiomycetidae > Eurotiales > Aspergillaceae > Aspergillus > Aspergillus subgen. Fumigati
Accessions
- Primary accessionA0A2I1C3W7
Proteomes
Organism-specific databases
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000453435 | 1-151 | Decarboxylase nsrE | ||
Interaction
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length151
- Mass (Da)17,556
- Last updated2018-02-28 v1
- Checksum5D29020B5C3BE3F4
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
MSZS01000005 EMBL· GenBank· DDBJ | PKX92305.1 EMBL· GenBank· DDBJ | Genomic DNA |