Structural analysis of PKS1, a polyketide synthase gene involved in melanin biosynthesis in Colletotrichum lagenarium

• Published in: Molecular & general genetics Vol. 249; no. 2; p. 162
• Main Authors: Takano, Y, Kubo, Y, Shimizu, K, Mise, K, Okuno, T, Furusawa, I. (Kyoto Univ. (Japan). Furusawa Lab. of Plant Pathology. Faculty of Agriculture)
• Format: Journal Article
• Language: English
• Published: Germany 15.11.1995
• Subjects: ALBINISME; ALBINISMO; Amino Acid Sequence; Base Sequence; Binding Sites; BIOSINTESIS; BIOSYNTHESE; COLLETOTRICHUM; DNA Primers; Exons; GENE; GENES; Genes, Fungal; Introns; LIGASAS; LIGASE; Melanins - biosynthesis; Mitosporic Fungi - enzymology; Mitosporic Fungi - genetics; Molecular Sequence Data; Multienzyme Complexes - genetics; Multienzyme Complexes - metabolism; Mutagenesis, Insertional; MUTANT; MUTANTES; Open Reading Frames; PIGMENT; PIGMENTOS; Polymerase Chain Reaction; Recombinant Proteins - metabolism; Restriction Mapping; Sequence Homology, Amino Acid; Transcription, Genetic
• ISSN: 0026-8925; 1432-1874
• DOI: 10.1007/bf00290362

Albino mutants (Pks(-)) of Colletotrichum lagenarium form nonmelanized appressoria and possess little penetrating ability on the host plant. The defect in albino mutant 79215 (Pks(-)) is considered to lie in pentaketide biosynthesis and/or pentaketide cyclization during melanin biosynthesis. The cosmid pAC7, carrying the PKS1 gene, when transformed into the albino mutant restores the wild-type melanin phenotype. The DNA sequence and the transcriptional organization of the PKS1 gene were determined. The PKS1 gene contains one open reading frame, consisting of 3 exons separated by two short introns. The predicted PKS1 polypeptide consists of 2187 amino acids and shows significant similarities with other polyketide synthases, particularly that encoded by wA in Aspergillus nidulans, involved in conidial pigmentation. The PKS1 gene contains highly conserved beta-ketoacyl synthase, acetyl/malonyl transferase, and acyl carrier protein domains. It is proposed that the C. lagenarium PKS1 gene encodes a polyketide synthase involved in melanin biosynthesis.