Ug. Hinz et al., THE GENE CODING FOR THE DOPA DIOXYGENASE INVOLVED IN BETALAIN BIOSYNTHESIS IN AMANITA-MUSCARIA AND ITS REGULATION, MGG. Molecular & general genetics, 256(1), 1997, pp. 1-6
Genomic and cDNA clones derived from the gene (dodA) coding for DOPA d
ioxygenase, a key enzyme in the betalain pathway, were obtained from t
he basidiomycete Amanita muscaria. A cDNA library was established in t
he phage lambda ZapII and dodA clones were isolated using polyclonal a
ntibodies raised against the purified enzyme. Their identity was confi
rmed by comparison of the deduced amino acid sequence with the sequenc
e of several tryptic peptide fragments of DOPA dioxygenase. The gene c
oded for a 228-amino acid protein that showed no homology to published
sequences. The coding region was interrupted by five short introns. R
egulation was shown to occur at the transcriptional level; the mRNA ac
cumulated to high levels only in the coloured cap tissue. dodA was fou
nd to be a single-copy gene in A. muscaria. To our knowledge, this is
the first gene from the betalain pathway to be cloned. It encodes a ty
pe of aromatic ring-cleaving dioxygenase that has not been previously
described.