Genetic and Biochemical Map for the Biosynthesis of Occidiofungin, an Antifungal Produced by Burkholderia contaminans Strain MS14

Abstract

A striking feature of Burkholderia contaminans strain MS14 is the production of a glycolipopeptide named occidiofungin. Occidiofungin has a broad range of antifungal activities against plant and animal pathogens. In this study, a complete covalent structure characterization and identification of the whole genomic DNA region for the occidiofungin gene (ocf) cluster are described. Discovery of the presence of 2,4-diaminobutyric acid and 3-chloro-␤-hydroxytyrosine and elucidation of the structure of a novel C 18 fatty amino acid residue have been achieved. In addition, seven additional putative open reading frames (the genes from ocfI to ocfN [ocfI-N] and ORF16) were identified. Transcription of all the putative genes ocfI-N identified in the region except ORF16 was regulated by both ambR1 and ambR2. Elucidation of the structure and the ocf gene cluster provides insight into the biosynthesis of occidiofungin and promotes future aims at understanding the biosynthetic machinery. This work provides new avenues for optimizing the production and synthesis of structural analogs of occidiofungin.

The Burkholderia contaminans MS14 ocfC Gene Encodes a Xylosyltransferase for Production of the Antifungal Occidiofungin

“…A glycopeptide named occidiofungin produced by strain MS14 is responsible for its antifungal activity (4,5). It is a cyclic glycopeptide made up of eight amino acids and one xylose (6). Four variants, named occidiofungin A, B, C, and D, have been identified from the MS14 strain culture (6).…”

“…It is a cyclic glycopeptide made up of eight amino acids and one xylose (6). Four variants, named occidiofungin A, B, C, and D, have been identified from the MS14 strain culture (6). Occidiofungin inhibits the growth of a broad range of fungal pathogens, and it was shown to inhibit the production of the cell wall of Geotrichum candidum (6).…”

“…Four variants, named occidiofungin A, B, C, and D, have been identified from the MS14 strain culture (6). Occidiofungin inhibits the growth of a broad range of fungal pathogens, and it was shown to inhibit the production of the cell wall of Geotrichum candidum (6). The compounds have shown great potential for pharmaceutical and agricultural applications (7,8).…”

“…Sixteen genes have been predicted in the ocf gene cluster, including the genes encoding nonribosomal peptide synthetases (ocfD, ocfE, ocfF, ocfH, and ocfJ), the bacterial LuxR regulatory proteins (ambR1 and ambR2), and an ATP-binding cassette (ocfA) (6). Mutagenesis and sequence analysis revealed that these genes are associated with occidiofungin production by strain MS14.…”

Identification of a Gene Encoding Adenylate Kinase Involved in Antifungal Activity Expression of the Biocontrol Strain Burkholderia pyrrocinia CH-67

“…These organisms can produce a large variety of antifungal compounds, such as cepacidine (Lee et al, 1994), pyrrolnitrin (Jayaswal et al, 1993), xylocandins (Meyers et al, 1987), and siderophores (Sokol et al, 1992). Most recently purified and identified antibiotic from Burkholderia contaminans with antibacterial and antifungal activity was occidiofungin, a unique antifungal glycolipopetide (Gu et al, 2011;Lu et al, 2009). Discovery of occidiofungin and its biosynthetic gene cluster brought some potential of new antimicrobial compound discovery from Burkholderia species.…”