B6H060 · PRX6_PENRW

Function

function

Short-chain dehydrogenase/reductase; part of the gene cluster that mediates the biosynthesis of PR-toxin, a bicyclic sesquiterpene belonging to the eremophilane class and acting as a mycotoxin (PubMed:24239699).
The first step of the pathway is catalyzed by the aristolochene synthase which performs the cyclization of trans,trans-farnesyl diphosphate (FPP) to the bicyclic sesquiterpene aristolochene (PubMed:24239699).
Following the formation of aristolochene, the non-oxygenated aristolochene is converted to the trioxygenated intermediate eremofortin B, via 7-epi-neopetasone (PubMed:24239699).
This conversion appears to involve three enzymes, a hydroxysterol oxidase-like enzyme, the quinone-oxidase prx3 that forms the quinone-type-structure in the bicyclic nucleus of aristolochene with the C8-oxo group and the C-3 hydroxyl group, and the P450 monooxygenase prx9 that introduces the epoxide at the double bond between carbons 1 and 2 (By similarity) (PubMed:24239699).
No monoxy or dioxy-intermediates have been reported to be released to the broth, so these three early oxidative reactions may be coupled together (PubMed:24239699).
Eremofortin B is further oxidized by another P450 monooxygenase, that introduces a second epoxide between carbons 7 and 11 prior to acetylation to eremofortin A by the acetyltransferase prx11 (By similarity).
The second epoxidation may be performed by a second P450 monooxygenase (PubMed:24239699).
After the acetylation step, eremofortin A is converted to eremofortin C and then to PR-toxin (PubMed:24239699).
First the conversion of eremofortin A to eremofortin C proceeds by oxidation of the side chain of the molecule at C-12 and is catalyzed by the short-chain oxidoreductase prx1 (PubMed:24239699).
The cytochrome P450 monooxygenase prx8 also plays a role in this step (By similarity).
The primary alcohol formed at C-12 is finally oxidized by the short-chain alcohol dehydrogenase prx4 that forms PR-toxin (PubMed:24239699).

Pathway

Sesquiterpene biosynthesis.

Features

Showing features for binding site, active site.

TypeIDPosition(s)Description
Binding site27NADP+ (UniProtKB | ChEBI)
Binding site70NADP+ (UniProtKB | ChEBI)
Binding site97NADP+ (UniProtKB | ChEBI)
Active site174Proton acceptor
Binding site174NADP+ (UniProtKB | ChEBI)
Active site178Lowers pKa of active site Tyr
Binding site178NADP+ (UniProtKB | ChEBI)
Binding site208NADP+ (UniProtKB | ChEBI)
Binding site210NADP+ (UniProtKB | ChEBI)

GO annotations

AspectTerm
Molecular Functionoxidoreductase activity

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Short-chain dehydrogenase/reductase prx6
  • EC number
  • Alternative names
    • PR-toxin biosynthesis cluster protein 6

Gene names

    • Name
      prx6
    • ORF names
      Pc12g06270, PCH_Pc12g06270

Organism names

Accessions

  • Primary accession
    B6H060

Proteomes

Organism-specific databases

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004512181-298Short-chain dehydrogenase/reductase prx6

Expression

Induction

Expression and the subsequent production of PR-toxin take place under static culture conditions (oxygen limited), whereas no expression of the PR-toxin genes occurs under the strongly aerated conditions required for optimal penicillin production (PubMed:24239699).
There is a negative control of the transcription of the PR-toxin genes by the penicillin biosynthesis gene product(s), or by a regulatory peptide encoded by a small ORF inside the penicillin gene cluster (PubMed:24239699).

Structure

Family & Domains

Sequence similarities

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    298
  • Mass (Da)
    32,254
  • Last updated
    2008-12-16 v1
  • Checksum
    6FE84E5075846846
MGSYTEPRVAIVAGATSLTRDPLQSGIGIDLAKDLCSKGWKVACVGRRQEAGEALLKDLPQDRAYFFAADVSNYEQYASVFSKVHHLWGRIDALCANAGIVDTSSLYIYGSKNNGVDNIPPAPDLSVVDINYKGVVYGTQLAIHFMRHNPQPGGRIVVTGSIGAVFPHKTYPVYCGTKAAVNHFIRGVAPLLKQKENISINCVMPGIVNTPIVPPEMIAAVTPECITPVQTVLRGYETFLEDSTGMAGEILECSADKLIYYHMPKPGNGHITKRAVTVWEPLFRMSHGEVSGLPDAIP

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AM920427
EMBL· GenBank· DDBJ
CAP80254.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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