Abstract
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 language | English |
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Pages (from-to) | 68-74 |
Number of pages | 7 |
Journal | Journal of Biotechnology |
Volume | 284 |
DOIs | |
Publication status | Published - 20 Oct 2018 |
Keywords
- Asymmetric oxidation
- Biocatalysis
- Cyanobacteria
- Hydroxyamino acids
- L-leucine 5-dioxygenase
ASJC Scopus subject areas
- Biotechnology
- Bioengineering
- Applied Microbiology and Biotechnology