Abstract
The anamorphic fungus Glarea lozoyensis mutant strain 74030 is an overproducer of pneumocandin B0, which is chemically converted into Cancidas, a potent antibiotic against clinically important fungal pathogens. Pneumocandins are acylated, cyclic hexapeptides with unusual hydroxylated amino acids. With the Glarea lozoyensis genome, the first species from the large polyphyletic family Helotiaceae has been sequenced.
GENOME ANNOUNCEMENT
Glarea lozoyensis, formerly classified as Zalerion arboricola (2), is an anamorphic fungus belonging to the Leotiales group. It produces lipopeptides with antifungal activities called pneumocandins which belong to the group of the echinocandin antibiotics. The wild-type strain (ATCC 20868) produces pneumocandin A0 predominantly. In contrast, the strain sequenced here, 74030, which was obtained after two cycles of mutagenesis, is a pneumocandin B0 overproducer (6). The acylated cyclic hexapeptide compound inhibits the synthesis of fungal cell wall glucan (9). It is chemically converted into caspofungin acetate (Cancidas), a potential therapeutic agent against fungal infections (7).
Here we present the whole-genome shotgun sequence of Glarea lozoyenesis ATCC 74030. The sequencing was performed using an Illumina HiSeq 2000 sequencer with a paired-end library and an additional mate pair library. The genome was assembled into 581 scaffolds (1 kb; N50, 871 kb) containing 886 contigs with a total size of ∼38.6 Mb. A total of 7,904 protein-coding genes were predicted by GlimmerHMM 3.0.1 (3), a coding capacity similar to that of other Ascomycetes. Out of these genes, 53.77% were assigned to putative functions based on similarity searches against Swiss-Prot (UniProtKB). The overall G+C content is 46.051. Additionally, 131 tRNA genes were predicted with tRNAscan-SE (5).
As pneumocandin B0 is composed of six amino acids and a 10,12-dimethylmyristoyl side chain, it is hypothesized that a nonribosomal peptide synthetase (NRPS) and a polyketide synthase (PKS) are involved in its biosynthesis (1). A preliminary genome analysis using the gene cluster prediction tools antiSMASH (8) and SMURF (4) gave three hybrid PKS-NRPS clusters and six NRPS predicted clusters. In two of the putative NRPS clusters, six module domains were detected, as expected for pneumocandin biosynthesis.
Nucleotide sequence accession numbers.
This Whole Genome Shotgun project has been deposited in DDBJ/EMBL/GenBank under accession no. GUE00000000. The version described in this article is the first version, AGUE01000000.
ACKNOWLEDGMENTS
We thank BaseClear (Leiden, Netherlands) for sequencing the Glarea lozoyensis genome, especially Walter Pirovano for helpful advice. We also thank Michael Müller for generous support and Gerald Bills for advice and contributions.
L.Y. was supported by an Alexander von Humboldt fellowship.
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