Q4WR21 · HELD1_ASPFU

Function

function

Acyltransferase; part of the gene cluster that mediates the biosynthesis of helvolic acid, an antibacterial nortriterpenoid (PubMed:19216560, PubMed:19415934, PubMed:29158519).
Protostadienol synthase helA cyclizes (3S)-oxidosqualene to (17Z)-protosta-1720,24-dien-3-beta-ol (protostadienol) (PubMed:19216560, PubMed:19415934, PubMed:29158519).
The synthesis of protostadienol is followed by several steps of monooxygenation, dehydrogenation, and acyl transfer to yield the final helvolic acid (PubMed:19216560).
Following the cyclization to the tetracyclic protostadienol by helA, cytochrome P450 monooxygenases helB1-mediated and helB2-mediated oxidation at C-4 and C-16, acyltransferase helD2-dependent acetylation of 16-OH, oxidation of C-21 by cytochrome P450 monooxygenase helB4, and short chain dehydrogenase helC-dependent oxidative decarboxylation yield the fusidane skeleton (PubMed:29158519).
This intermediate is further modified in three additional steps mediated by the cytochrome P450 monooxygenase helB3, the acyltransferase helD1, and the 3-ketosteroid 1-dehydrogenase helE to give helvolic acid (PubMed:19216560, PubMed:19415934, PubMed:29158519).
Compared with the late stages in the biosynthesis of helvolic acid, enzymes involved in the early stage modifications act in a relatively strict order (PubMed:29158519).
The hydroxylation of C-16 by helB1 and subsequent acetylation by helD2 should occur before the helB3-mediated oxidation of C-21 (PubMed:29158519).
C-4 demethylation in fusidane-type antibiotics proceeds in an unusual manner though it is also achieved by oxidative decarboxylation (PubMed:19415934, PubMed:29158519).
The methyl group at C-4 beta position is oxidized by helB1 and subsequently removed by the short chain dehydrogenase helC (PubMed:19415934, PubMed:29158519).

Pathway

Mycotoxin biosynthesis.

Features

Showing features for active site.

TypeIDPosition(s)Description
Active site145Proton acceptor
Active site415Proton acceptor

GO annotations

AspectTerm
Molecular Functionacyltransferase activity, transferring groups other than amino-acyl groups
Biological Processhelvolic acid biosynthetic process
Biological Processsecondary metabolic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Acyltransferase helD1
  • EC number
  • Alternative names
    • Helvolic acid biosynthesis cluster protein D1

Gene names

    • Name
      helD1
    • ORF names
      AFUA_4G14820

Organism names

Accessions

  • Primary accession
    Q4WR21

Proteomes

Organism-specific databases

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004419511-478Acyltransferase helD1

Expression

Induction

Expression is under the control of the secondary metabolism regulator laeA (PubMed:17432932).

Interaction

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Belongs to the plant acyltransferase family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    478
  • Mass (Da)
    53,274
  • Last updated
    2005-07-05 v1
  • Checksum
    6D5ACF3033D29E16
MESIPLSPFDLQGSFSNIPYAFFYENTQSENDFMPFDFLKGSLWASLQRFPILTGRLRARSTGHIVVEVDAGNPNQPDIRETLCDSVHWSQLKESSFAWDAWPAGVATVGPVATAAADGEIKLLNIHVMRLAQNSGVILFINIPHYVVDGVGYFAFINHWAETMRMQQQQQEQENEARSRFSFDRGIIQRYLPTERAPLDPLTASIYGQRNLLVDWLAWLSPTTLGGLLSKTAAMARGEAHLFRIPRASLDQVHKDVQPYIPASARLSDNDLLVALISKTYIQSQPQPKPPTGFLSWLRPGQGQPESHCTVRIPCDVRRHLKVRERYTGNLLLGMMVRTPLAELARPTSSETLAAAALNVRQSIERVQPGLVAAYHDLIQANPTSHMRPLAFTATRTTTSLVTTSQVRFPMYEADFGSGKPCFVCLTPVFAGSYTMAAILPTPEGREGGVYVLLTSNVEAMQGIKKNQYWNGLVEIIW

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AAHF01000005
EMBL· GenBank· DDBJ
EAL89313.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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