New biosynthetic step in the melanin pathway of Wangiella (Exophiala) dermatitidis: evidence for 2-acetyl-1,3,6,8-Tetrahydroxynaphthalene as a novel precursor.

ABSTRACT: The predominant cell wall melanin of Wangiella dermatitidis, a black fungal pathogen of humans, is synthesized from 1,8-dihydroxynaphthalene (D2HN). An early precursor, 1,3,6,8-tetrahydroxynaphthalene (T4HN), in the pathway leading to D2HN is reportedly produced directly as a pentaketide by an iterative type I polyketide synthase (PKS). In contrast, the bluish-green pigment in Aspergillus fumigatus is produced after the enzyme Ayg1p converts the PKS product, the heptaketide YWA1, to T4HN. Previously, we created a new melanin-deficient mutant of W. dermatitidis, WdBrm1, by random molecular insertion. From this strain, the altered gene WdYG1 was cloned by a marker rescue strategy and found to encode WdYg1p, an ortholog of Ayg1p. In the present study, two gene replacement mutants devoid of th

SUBMITTER: Wheeler MH 

PROVIDER: S-EPMC2568069 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature