A new reducing polyketide synthase gene from the lichen-forming fungus Cladonia metacorallifera
- Author:
- Kim J.A., Hong S.G., Cheong Y.H., Koh Y.J. & Hur J.-S.
- Year:
- 2012
- Journal:
- Mycologia
- Pages:
- 104(2): 362–370
- Url:
Lichens produce unique polyketide secondary
metabolites including depsides, depsidones,
dibenzofurans and depsones. The biosynthesis of
these compounds is governed by polyketide synthase
(PKS), but the mechanism via which they are
produced has remained unclear until now. We
reported the 6-methylsalicylic acid synthase (6-MSAS)
type of PKS gene, which is a member of the fungalreducing
PKSs. A cultured mycobiont of Cladonia
metacorallifera was employed in the isolation and
characterization of a polyketide synthase gene
(CmPKS1). The complete sequence information for
CmPKS1 was acquired via the screening of a Fosmid
genomic library with a 456 bp fragment corresponding
to part of the acyl transferase (AT) domain as a
probe. CmPKS1 contains b-ketoacyl synthase (KS),
AT, dehydratase (DH), ketoreductase (KR) and
phosphopantetheine attachment site (PP) domains.:
The domain organization of CmPKS1 (KSAT-
DH-KR-PP) is a typical 6-MSAS-type PKS, and the
results of phylogenetic analysis showed that CmPKS1
grouped with other fungal-reducing PKSs. Quantitative
real time PCR analyses showed that CmPKS1 was
expressed preferentially in the early growth stage of
the axenically cultured mycobiont. Furthermore
CmPKS1 expression was found to be dependent on
the carbon sources and concentrations in the
medium.
Key words: Cladonia metacorallifera, culture, fungal-
reducing PKS, lichen-forming fungus, Polyketide
synthase.
- Id:
- 22100
- Submitter:
- zdenek
- Post_time:
- Tuesday, 24 July 2012 17:33