Q5AR50 · ASQG_EMENI

Function

function

FAD-dependent monooxygenase; part of the gene cluster that mediates the biosynthesis of the aspoquinolone mycotoxins (PubMed:25251934, PubMed:28114276).
Within the pathway, the FAD-dependent monooxygenase asqG catalyzes the epoxidation of the terminal C7'-C8' olefin to produce the intermediate [(1'E)-5'-(3',3'-dimethyloxiran-2'-yl)-3'-hydroxy-3'-methylpent-1'-en-1'-yl]-quinolinone B (PubMed:28114276).
The first step of the pathway is catalyzed by the nonribosomal peptide synthetase asqK that condenses anthranilic acid and O-methyl-L-tyrosine to produce 4'-methoxycyclopeptin. 4'-methoxycyclopeptin is then converted to 4'-methoxydehydrocyclopeptin by the ketoglutarate-dependent dioxygenase asqJ. AsqJ also converts its first product 4'-methoxydehydrocyclopeptin to 4'-methoxycyclopenin. The following conversion of 4'-methoxycyclopenin into 4'-methoxyviridicatin is catalyzed by the cyclopenase asqI. 4'-methoxyviridicatin is the precursor of quinolone natural products, and is further converted to quinolinone B. The prenyltransferase asqH1 then catalyzes the canonical Friedel-Crafts alkylation of quinolinone B with dimethylallyl cation to yield dimethylallyl quinolone, which is subjected to FAD-dependent dehydrogenation by the FAD-linked oxidoreductase asqF to yield conjugated aryl diene. The delta(3') double bond then serves as the site of the second alkylation with DMAPP catalyzed by the prenyltransferase asqH2 to yield a carbenium ion intermediate, which can be attacked by H2O to yield a styrenyl quinolone containing a C3'-hydroxyprenyl chain. The FAD-dependent monooxygenase asqG performs epoxidation of the terminal C7'-C8' olefin. Finally, after dehydratation of the epoxide at C3 by asqC, the quinolone epoxide rearrangement protein asqO catalyzes an enzymatic 3-exo-tet cyclization to yield the cyclopropyl-THF ring system in aspoquinolone (Probable).

Catalytic activity

Cofactor

FAD (UniProtKB | Rhea| CHEBI:57692 )

Pathway

Secondary metabolite biosynthesis.
Alkaloid biosynthesis.
Mycotoxin biosynthesis.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site33FAD (UniProtKB | ChEBI)
Binding site47FAD (UniProtKB | ChEBI)
Binding site113FAD (UniProtKB | ChEBI)
Binding site313FAD (UniProtKB | ChEBI)
Binding site326FAD (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentmembrane
Molecular FunctionFAD binding
Molecular Functionmonooxygenase activity
Biological Processsecondary metabolite biosynthetic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    FAD-dependent monooxygenase asqG
  • EC number
  • Alternative names
    • 4'-methoxyviridicatin/aspoquinolone biosynthesis cluster protein asqG
    • Aspoquinolone biosynthesis protein G

Gene names

    • Name
      asqG
    • ORF names
      AN9230

Organism names

Accessions

  • Primary accession
    Q5AR50
  • Secondary accessions
    • C8VJP9

Proteomes

Subcellular Location

Membrane
; Multi-pass membrane protein

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane448-468Helical
Transmembrane482-502Helical

Keywords

PTM/Processing

Features

Showing features for signal, chain.

TypeIDPosition(s)Description
Signal1-19
ChainPRO_000043761820-566FAD-dependent monooxygenase asqG

Interaction

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    566
  • Mass (Da)
    61,875
  • Last updated
    2005-04-26 v1
  • Checksum
    D2B220D263CC2D82
MAAFTVIIIGGSISGLTLANVLEKYGIKYILLEKRPSIGPQLGATVVVHPSGLHLLSQLGLRERVEELATPVELQKAIGPDGTFVLNIAATNQCDRTIADALSTGYMPMFIARQDLIKVLYDNLQDKFRVHASLGLRELEWAGDKVKVTTTDGTSVVGDIVVGADGANSRTRAEIWKIADVEDPSYGSQQLAKSIACTYRCVFGMVDDGDSSLARTAYLAFQYNRAYTYLPTDSGRAYFLAFFKNPAKTVNDAIPRYSDQDEDADVAAHANDIIVPGLTFGDLYKRRTRCTLVPLQEYLLDKCFYKRVVLIGDAVHKLNPITGRGANLAIEGAALLGDLIKHALEKSLQPTDEMLQTAFFTYQQCTKSRAPSQIDDAHRVQSLAALENPLLKFMSLKLLKRATADKLALGVAVDFSTGHSMRYLPQLPQRGMVPLNKDVVANPEHRPASSTVLWIILMLGMASLGAVWQKHQRAEEDQPIHGYTLLTLSTFYNLMILFASAVHGSLGRRAVNLSFSDDSGMVPFYAVGHAPDKYRPTTPSRRVGLLVPGPSYLGSGGHFNGLLEVA

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
BN001306
EMBL· GenBank· DDBJ
CBF82272.1
EMBL· GenBank· DDBJ
Genomic DNA
AACD01000170
EMBL· GenBank· DDBJ
EAA61521.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp