Identification of OxyE as an Ancillary Oxygenase during Tetracycline Biosynthesis
✍ Scribed by Peng Wang; Wenjun Zhang; Jixun Zhan; Yi Tang
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 263 KB
- Volume
- 10
- Category
- Article
- ISSN
- 1439-4227
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✦ Synopsis
Abstract
Ancillary oxygenase: OxyE is identified as a likely ancillary C‐4 hydroxylase used during oxytetracycline biosynthesis in Streptomyces rimosus. The synergistic actions of oxygenases OxyE and OxyL ensure complete oxidative tailoring and prevent irreversible shunt modifications of the biosynthetic intermediate.magnified image
The double hydroxylation of 6‐pretetramid to 4‐keto‐anhydrotetracycline is a key tailoring reaction during the biosynthesis of the broad‐spectrum antibiotic tetracyclines. It has been shown previously by heterologous reconstitution that OxyL is a dioxygenase and is the only enzyme required to catalyze the insertion of oxygen atoms at the C‐12a and C‐4 positions. We report here that OxyE, a flavin adenine dinucleotide (FAD)‐dependent hydroxylase homologue, is an ancillary mono‐oxygenase for OxyL during oxytetracycline biosynthesis in Streptomyces rimosus__. By using both gene disruption and heterologous reconstitution approaches, we demonstrated that OxyE plays a nonessential, but important role in oxytetracycline biosynthesis by serving as a more efficient C‐4 hydroxylase. In addition, we demonstrated that partially oxidized biosynthetic intermediates can undergo various glycosylation modifications in__ S. rimosus__. Our results indicate that the synergistic actions of OxyE and OxyL in the double hydroxylation step prevent accumulation of shunt products during oxytetracycline biosynthesis in__ S. rimosus__.__