A0A2G5ICC7 · CTB7_CERBT
- ProteinMonooxygenase CTB7
- GeneCTB7
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids419 (go to sequence)
- Protein existenceInferred from homology
- Annotation score2/5
Function
function
Monooxygenase; part of the gene cluster that mediates the biosynthesis of cercosporin, a light-activated, non-host-selective toxin (By similarity).
The perylenequinone chromophore of cercosporin absorbs light energy to attain an electronically-activated triplet state and produces active oxygen species such as the hydroxyl radical, superoxide, hydrogen peroxide or singlet oxygen upon reaction with oxygen molecules (PubMed:11701851).
These reactive oxygen species cause damage to various cellular components including lipids, proteins and nucleic acids (PubMed:11701851).
The first step of cercosporin biosynthesis is performed by the polyketide synthase CTB1 which catalyzes the formation of nor-toralactone (By similarity).
The starter unit acyltransferase (SAT) domain of CTB1 initiates polyketide extension by the selective utilization of acetyl-CoA, which is elongated to the heptaketide in the beta-ketoacyl synthase (KS) domain by successive condensations with six malonyl units introduced by the malonyl acyltransferase (MAT) domain. The product template (PT) domain catalyzes C4-C9 and C2-C11 aldol cyclizations and dehydrations to a trihydroxynaphthalene, which is thought to be delivered to the thioesterase (TE) domain for product release (By similarity).
The bifunctional enzyme CTB3 then methylates nor-toralactone to toralactone before conducting an unusual oxidative aromatic ring opening (By similarity).
The O-methyltransferase CTB2 further methylates the nascent OH-6 of the CBT3 product, blocking further oxidation at this site before the reductase CTB6 reduces the 2-oxopropyl ketone at position C7, giving naphthalene (By similarity).
The FAD-dependent monooxygenase CTB5 in concert with the multicopper oxidase CTB12 are responsible for homodimerization of naphthalene with CTB7 installing the dioxepine moiety, finally producing cercosporin (By similarity).
The fasciclin domain-containing protein CTB11 might act with CTB5 and CTB12 whereas the roles of CTB9 and CTB10 have still to be elucidated (By similarity).
The perylenequinone chromophore of cercosporin absorbs light energy to attain an electronically-activated triplet state and produces active oxygen species such as the hydroxyl radical, superoxide, hydrogen peroxide or singlet oxygen upon reaction with oxygen molecules (PubMed:11701851).
These reactive oxygen species cause damage to various cellular components including lipids, proteins and nucleic acids (PubMed:11701851).
The first step of cercosporin biosynthesis is performed by the polyketide synthase CTB1 which catalyzes the formation of nor-toralactone (By similarity).
The starter unit acyltransferase (SAT) domain of CTB1 initiates polyketide extension by the selective utilization of acetyl-CoA, which is elongated to the heptaketide in the beta-ketoacyl synthase (KS) domain by successive condensations with six malonyl units introduced by the malonyl acyltransferase (MAT) domain. The product template (PT) domain catalyzes C4-C9 and C2-C11 aldol cyclizations and dehydrations to a trihydroxynaphthalene, which is thought to be delivered to the thioesterase (TE) domain for product release (By similarity).
The bifunctional enzyme CTB3 then methylates nor-toralactone to toralactone before conducting an unusual oxidative aromatic ring opening (By similarity).
The O-methyltransferase CTB2 further methylates the nascent OH-6 of the CBT3 product, blocking further oxidation at this site before the reductase CTB6 reduces the 2-oxopropyl ketone at position C7, giving naphthalene (By similarity).
The FAD-dependent monooxygenase CTB5 in concert with the multicopper oxidase CTB12 are responsible for homodimerization of naphthalene with CTB7 installing the dioxepine moiety, finally producing cercosporin (By similarity).
The fasciclin domain-containing protein CTB11 might act with CTB5 and CTB12 whereas the roles of CTB9 and CTB10 have still to be elucidated (By similarity).
Pathway
Mycotoxin biosynthesis.
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | FAD binding | |
Molecular Function | monooxygenase activity |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameMonooxygenase CTB7
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Fungi > Dikarya > Ascomycota > Pezizomycotina > Dothideomycetes > Dothideomycetidae > Mycosphaerellales > Mycosphaerellaceae > Cercospora
Accessions
- Primary accessionA0A2G5ICC7
Proteomes
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000449871 | 1-419 | Monooxygenase CTB7 | |||
Sequence: MASSNRRVLVNGGGPAGAVTAFWLAKGGFEVVVTERSMSRPYGQGVDVTGRASDIIKKMGLEQRIRDSTTGEAGLTVVDDQGEDVAPPLGTAPIEGGTASVTQEIEIMRRDLTKIFVDAAEALPNVTFRYGCTVDEVQQHEKSITAVLSDTGKPEDFTAIIGADGLGSAIRKLTFDPEINRRSVSPTNTYVAFFSIPGDPKYDTPVGKLQHANKGRGILVRPIDKKGTQRSCYLMSQSDSQELAQVARTGSQEDQKALLDNRFREFTGPLGKRAVEGMHSADDFYFTRIVQIKLDSWHSGRAALVGDAGYSPSPLTGQGTTLAIIGAYVLAGEMAKSPDDLERAFTSYYAILNKFVSESQEIPFGGQAPKLILPQSDWGIWLLRTFYKIISWTGIWRLLNFGNETVKVELPEYDFGGLD |
Structure
Family & Domains
Sequence similarities
Belongs to the aromatic-ring hydroxylase family. KMO subfamily.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length419
- Mass (Da)45,616
- Last updated2018-01-31 v1
- Checksum17439B57047D1E80