Characterization of a fungal thioesterase having Claisen cyclase and deacetylase activities in melanin biosynthesis.

ABSTRACT: Melanins are a broad class of darkly pigmented macromolecules formed by oxidative polymerization of phenolic monomers. In fungi, melanins are known virulence factors that contribute to pathogenicity. Their biosynthesis generally involves polymerization of 1,8-dihydroxynaphthalene via a 1,3,6,8-tetrahydroxynaphthalene (THN) precursor assembled by multidomain, nonreducing polyketide synthases. Convergent routes to THN have evolved in fungi. Parallel heptaketide and hexaketide pathways exist that utilize conventional C-terminal thioesterase/Claisen cyclase domains and separate side-chain deacylases. Here, in vitro characterization of Pks1 from Colletotrichum lagenarium establishes a true THN synthase with a bifunctional thioesterase (TE) catalyzing both cyclization and deacetylation of an enz

SUBMITTER: Vagstad AL 

PROVIDER: S-EPMC3530136 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature