Cloning and characterization of a new delta-specific L-leucine dioxygenase from Anabaena variabilis

Raquel S. Correia Cordeiro, Junichi Enoki, Florian Busch, Carolin Mügge, Robert Kourist*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Optically pure hydroxy amino acids show several bioactivities and are valuable building blocks for the pharmaceutical industry. Fe(II)/α-ketoglutarate dependent dioxygenases catalyze the hydroxylation or sulfoxidation of L-amino acids with high regio- and stereoselectivity. While several β- and γ-specific enzymes have been described, only one δ-specific hydroxylase has been reported so far. Based on its similarity to the known L-leucine 5-hydroxylase from Nostoc punctiforme, an open reading frame from the cyanobacterium Anabaena variabilis was identified as putative L-leucine dioxygenase (AvLDO). Here we report the cloning and characterization of this dioxygenase. The enzyme showed a high preference for acidic conditions and moderate reaction temperatures. AvLDO catalyzed the regio- and stereoselective hydroxylation of several aliphatic amino acids in δ-position. In case of the sulfoxidation of L-methionine, AvLDO produced the opposite diastereomer than isoleucine dioxygenase. AvLDO is thus an interesting addition to the toolbox of Fe(II)/α-ketoglutarate dependent dioxygenases. On the genomic DNA of Anabaena variabilis ATCC 29413, the avldo gene is located on a gene cluster involved (2S,4S)-4-methylproline biosynthesis, which is contained in bioactive peptides often found from cyanobacteria. This fact suggests the metabolic functional role of this amino acid dioxygenase in cyanobacteria.

Original languageEnglish
Pages (from-to)68-74
Number of pages7
JournalJournal of Biotechnology
Publication statusPublished - 20 Oct 2018


  • Asymmetric oxidation
  • Biocatalysis
  • Cyanobacteria
  • Hydroxyamino acids
  • L-leucine 5-dioxygenase

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology

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