Diversity in Fungal Intermolecular Phenol Coupling of Polyketides: Regioselective Laccase-Based Systems.
Chembiochem
; 20(15): 1928-1932, 2019 08 01.
Article
en En
| MEDLINE
| ID: mdl-30868712
Polyketides form a structurally diverse and pharmaceutically important class of secondary metabolites. Both diversity and biological activity are largely facilitated by post-polyketide synthase tailoring including methylation, oxidation, reduction, glycosylation, and dimerization. Cytochrome P450 enzymes (CYPs), flavin-dependent monooxygenases (FMOs), and laccases are known to catalyze phenol coupling in the biosynthesis of polyketide dimers. Polyketide homodimers resulting from enzyme catalysis are often formed in a highly regio- and stereoselective manner, in contrast to analogous nonenzymatic dimerization. Although it is known that CYPs and FMOs are capable of selectively generating one of several putative isomers, hitherto described laccases depend on auxiliary proteins to achieve similar selectivity. Herein, regioselective phenol coupling catalyzed by a fungal laccase is demonstrated. The heterologously produced Av-VirL from Aspergillus viridinutans selectively generated the 6,6'-homodimer of (R)-semivioxanthin. Genome analysis is used to show that laccase-based phenol-coupling systems are widespread in fungi. Homologues of Av-VirL were identified in the putative biosynthetic gene clusters of vioxanthin, xanthomegnin, and xanthoepocin, and of the perylenequinones hypocrellinâ
A, elsinochromeâ
A, and cercosporin. These findings show that laccases are capable of selective phenol coupling in the absence of auxiliary proteins.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fenoles
/
Lacasa
/
Policétidos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Chembiochem
Asunto de la revista:
BIOQUIMICA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Alemania