A Zn(II)2Cys6 DNA binding protein regulates the sirodesmin PL biosynthetic gene cluster in Leptosphaeria maculans

• Published in: Fungal genetics and biology 2008-05, Vol.45 (5), p.671-682
• Main Authors: Fox, Ellen M., Gardiner, Donald M., Keller, Nancy P., Howlett, Barbara J.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Anti-Bacterial Agents - metabolism; Anti-Bacterial Agents - pharmacology; Ascomycota - genetics; Ascomycota - physiology; Aspergillus; Bacillus subtilis - drug effects; Binding Sites; bioinformatics; Biosynthetic Pathways - genetics; DNA-binding proteins; DNA-Binding Proteins - genetics; DNA-Binding Proteins - physiology; ETP; fungal proteins; Fungal Proteins - genetics; Fungal Proteins - physiology; Gene Deletion; gene expression; Gene Expression Profiling; gene expression regulation; Gene Expression Regulation, Fungal; Gene Order; Gene Silencing; genetic complementation; Genetic Complementation Test; genetic transformation; Gliotoxin; Leptosphaeria; Leptosphaeria maculans; Microbial Sensitivity Tests; Molecular Sequence Data; Multigene Family; mutation; mycotoxins; nucleotide sequences; Piperazines - metabolism; Piperazines - pharmacology; plant pathogenic fungi; promoter regions; Promoter Regions, Genetic; regulatory proteins; RNA, Fungal - biosynthesis; RNA, Messenger - biosynthesis; Sequence Analysis; Sequence Homology, Amino Acid; Sirodesmin; Toxin; transcription (genetics); Zn(II)2Cys6
• ISSN: 1087-1845; 1096-0937
• DOI: 10.1016/j.fgb.2007.10.005

A gene, sirZ, encoding a Zn(II)2Cys6 DNA binding protein is present in a cluster of genes responsible for the biosynthesis of the epipolythiodioxopiperazine (ETP) toxin, sirodesmin PL in the ascomycete plant pathogen, Leptosphaeria maculans. RNA-mediated silencing of sirZ gives rise to transformants that produce only residual amounts of sirodesmin PL and display a decrease in the transcription of several sirodesmin PL biosynthetic genes. This indicates that SirZ is a major regulator of this gene cluster. Proteins similar to SirZ are encoded in the gliotoxin biosynthetic gene cluster of Aspergillus fumigatus (gliZ) and in an ETP-like cluster in Penicillium lilacinoechinulatum (PlgliZ). Despite its high level of sequence similarity to gliZ, PlgliZ is unable to complement the gliotoxin-deficiency of a mutant of gliZ in A. fumigatus. Putative binding sites for these regulatory proteins in the promoters of genes in these clusters were predicted using bioinformatic analysis. These sites are similar to those commonly bound by other proteins with Zn(II)2Cys6 DNA binding domains.