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

Wood sapstain, a cosmetic defect that results in significant economical loss to forest-products industries, is caused by mycelial melanization of the wood-colonizing ophiostomatoid fungi. To improve our understanding of how melanin biosynthesis is regulated in the cosmopolitan sapstaining fungus, Ophiostoma piceae, we used insertional mutagenesis. Insertional mutants were generated by restriction enzyme-mediated integration (REMI) and Agrobacterium-mediated integration (AMI). We screened 1,053 REMI and 1,083 AMI transformants and found 30 mutants with impaired growth or pigmentation. We characterized four AMI transformants in more detail, in which the T-DNA integrated at a single locus. The albino mutant TOPA45 had incorporated the T-DNA in a polyketide synthase gene (PKS1). The mutants TOPA1 and TOPA1076 displayed reduced pigmentation. In TOPA1, the T-DNA was inserted into a gene that encodes a putative protein kinase activator whereas, for TOPA1076, it was inserted into a gene that encodes a protein with unknown function. Finally, the vegetative hyphae of mutant TOPA814 were not melanized, whereas the synnemata displayed the same level of pigmentation as the wild type. In the TOPA814 mutant, segregation analysis revealed that the mutant phenotype was not linked to the T-DNA insertion locus but to a translocation from the PIG1 locus to the left border of the T-DNA. The protein predicted for the PIG1 locus had a middle homology region that was specific to fungal transcription factors.

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Isolation of Abikoviromycin and Dihydroabikoviromycin as Inhibitors of Polyketide Synthase Involved in Melanin Biosynthesis by Colletotrichum lagenarium.

ChemInform ◽

10.1002/chin.200411207 ◽

2004 ◽

Vol 35 (11) ◽

Author(s):

Hiroki Maruyama ◽

Susumu Okamoto ◽

Yasuyuki Kubo ◽

Gento Tsuji ◽

Isao Fujii ◽

...

Keyword(s):

Polyketide Synthase ◽

Colletotrichum Lagenarium ◽

Melanin Biosynthesis

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Insertional mutagenesis and characterization of a polyketide synthase gene () required for melanin biosynthesis in

FEMS Microbiology Letters ◽

10.1016/j.femsle.2004.07.007 ◽

2004 ◽

Vol 238 (1) ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

A MORIWAKI ◽

J KIHARA ◽

T KOBAYASHI ◽

T TOKUNAGA ◽

S ARASE ◽

...

Keyword(s):

Insertional Mutagenesis ◽

Polyketide Synthase ◽

Melanin Biosynthesis ◽

Polyketide Synthase Gene

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Cloning and structural analysis of the melanin biosynthesis gene SCD1 encoding scytalone dehydratase in Colletotrichum lagenarium.

Applied and Environmental Microbiology ◽

10.1128/aem.62.12.4340-4344.1996 ◽

1996 ◽

Vol 62 (12) ◽

pp. 4340-4344 ◽

Cited By ~ 66

Author(s):

Y Kubo ◽

Y Takano ◽

N Endo ◽

N Yasuda ◽

S Tajima ◽

...

Keyword(s):

Structural Analysis ◽

Colletotrichum Lagenarium ◽

Melanin Biosynthesis ◽

Biosynthesis Gene ◽

Scytalone Dehydratase

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Genetic Relationships in the Toxin-Producing Fungal Endophyte, Alternaria oxytropis Using Polyketide Synthase and Non-Ribosomal Peptide Synthase Genes

Journal of Fungi ◽

10.3390/jof7070538 ◽

2021 ◽

Vol 7 (7) ◽

pp. 538

Author(s):

Rebecca Creamer ◽

Deana Baucom Hille ◽

Marwa Neyaz ◽

Tesneem Nusayr ◽

Christopher L. Schardl ◽

...

Keyword(s):

Amino Acid ◽

Polyketide Synthase ◽

Genetic Relationships ◽

Protein Sequences ◽

Fungal Endophyte ◽

Melanin Synthesis ◽

Melanin Biosynthesis ◽

Protein Levels ◽

Oxytropis Sericea ◽

And Function

The legume Oxytropis sericea hosts a fungal endophyte, Alternaria oxytropis, which produces secondary metabolites (SM), including the toxin swainsonine. Polyketide synthase (PKS) and non-ribosomal peptide synthase (NRPS) enzymes are associated with biosynthesis of fungal SM. To better understand the origins of the SM, an unannotated genome of A. oxytropis was assessed for protein sequences similar to known PKS and NRPS enzymes of fungi. Contigs exhibiting identity with known genes were analyzed at nucleotide and protein levels using available databases. Software were used to identify PKS and NRPS domains and predict identity and function. Confirmation of sequence for selected gene sequences was accomplished using PCR. Thirteen PKS, 5 NRPS, and 4 PKS-NRPS hybrids were identified and characterized with functions including swainsonine and melanin biosynthesis. Phylogenetic relationships among closest amino acid matches with Alternaria spp. were identified for seven highly conserved PKS and NRPS, including melanin synthesis. Three PKS and NRPS were most closely related to other fungi within the Pleosporaceae family, while five PKS and PKS-NRPS were closely related to fungi in the Pleosporales order. However, seven PKS and PKS-NRPS showed no identity with fungi in the Pleosporales or the class Dothideomycetes, suggesting a different evolutionary origin for those genes.

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Relation between pigment intensity and penetrating ability in appressoria of Colletotrichum lagenarium

Canadian Journal of Microbiology ◽

10.1139/m87-152 ◽

1987 ◽

Vol 33 (10) ◽

pp. 870-873 ◽

Cited By ~ 14

Author(s):

Yasuyuki Kubo ◽

Iwao Furusawa ◽

Jiko Shishiyama

Keyword(s):

Parent Strain ◽

Colletotrichum Lagenarium ◽

Melanin Biosynthesis ◽

Glass Slides ◽

Albino Mutant

Mutant 8004 of Colletotrichum lagenarium formed slightly pigmented appressoria. The appressoria germinated laterally on glass slides, but could penetrate nitrocellulose membranes. The slightly pigmented appressoria of the albino mutant 79215 were observed to behave in a similar manner when treated with 100 μM scytalone. The appressorial pigmentation of mutant 8004 was increased by the application of scytalone, and mature appressorial pigmentation, indistinguishable from that of the parent strain 104-T, was observed when appressoria were treated with 100 μM scytalone, a lower concentration than that needed for mature pigmentation of the albino mutant. The sensitivity to tricyclazole of appressorial pigmentation of mutant 8004 was higher than that of the parent strain 104-T. These results suggest that, although melanin biosynthesis is essential for appressorial penetration, slight pigmentation is sufficient.

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