A0A2G5ICC7 · CTB7_CERBT

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).

Pathway

Mycotoxin biosynthesis.

GO annotations

AspectTerm
Molecular FunctionFAD binding
Molecular Functionmonooxygenase activity

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Monooxygenase CTB7
  • EC number
  • Alternative names
    • Cercosporin toxin biosynthesis cluster protein 7

Gene names

    • Name
      CTB7
    • ORF names
      CB0940_00836

Organism names

Accessions

  • Primary accession
    A0A2G5ICC7

Proteomes

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004498711-419Monooxygenase CTB7

Family & Domains

Sequence similarities

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    419
  • Mass (Da)
    45,616
  • Last updated
    2018-01-31 v1
  • Checksum
    17439B57047D1E80
MASSNRRVLVNGGGPAGAVTAFWLAKGGFEVVVTERSMSRPYGQGVDVTGRASDIIKKMGLEQRIRDSTTGEAGLTVVDDQGEDVAPPLGTAPIEGGTASVTQEIEIMRRDLTKIFVDAAEALPNVTFRYGCTVDEVQQHEKSITAVLSDTGKPEDFTAIIGADGLGSAIRKLTFDPEINRRSVSPTNTYVAFFSIPGDPKYDTPVGKLQHANKGRGILVRPIDKKGTQRSCYLMSQSDSQELAQVARTGSQEDQKALLDNRFREFTGPLGKRAVEGMHSADDFYFTRIVQIKLDSWHSGRAALVGDAGYSPSPLTGQGTTLAIIGAYVLAGEMAKSPDDLERAFTSYYAILNKFVSESQEIPFGGQAPKLILPQSDWGIWLLRTFYKIISWTGIWRLLNFGNETVKVELPEYDFGGLD

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
LKMD01000100
EMBL· GenBank· DDBJ
PIB02400.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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