Polyketide synthase gene coupled to the peptide synthetase module involved in the biosynthesis of the cyclic heptapeptide microcystin.
J Biochem
; 127(5): 779-89, 2000 May.
Article
em En
| MEDLINE
| ID: mdl-10788786
ABSTRACT
The peptide synthetase gene operon, which consists of mcyA, mcyB, and mcyC, for the activation and incorporation of the five amino acid constituents of microcystin has been identified [T. Nishizawa et al. (1999) J. Biochem. 126, 520-529]. By sequencing an additional 34 kb of DNA from microcystin-producing Microcystis aeruginosa K-139, we identified the residual microcystin synthetase gene operon, which consists of mcyD, mcyE, mcyF, and mcyG, in the opposite orientation to the mcyABC operon. McyD consisted of two polyketide synthase modules, and McyE contained a polyketide synthase module at the N-terminus and a peptide synthetase module at the C-terminus. McyF was found to exhibit similarity to amino acid racemase. McyG consisted of a peptide synthetase module at the N-terminus and a polyketide synthase at the C-terminus. The microcystin synthetase gene cluster was conserved in another microcystin-producing strain, Microcystis sp. S-70, which produces Microcystin-LR, -RR, and -YR. Insertional mutagenesis of mcyA, mcyD, or mcyE in Microcystis sp. S-70 abolished microcystin production. In conclusion, the mcyDEFG operon is presumed to be responsible for 3-amino-9-methoxy-2,6, 8-trimethyl-10-phenyldeca-4,6-dienoic acid (Adda) biosynthesis, and the incorporation of Adda and glutamic acid into the microcystin molecule.
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Base de dados:
MEDLINE
Assunto principal:
Peptídeo Sintases
/
Peptídeos Cíclicos
/
Cianobactérias
/
Genes Bacterianos
/
Complexos Multienzimáticos
Idioma:
En
Revista:
J Biochem
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Japão