Abstract
Streptomyces globisporus C-1027 is the producer of antitumor antibiotic C-1027, a nine-membered enediyne-containing compound. Here we present a draft genome sequence of S. globisporus C-1027 containing the intact biosynthetic gene cluster for this antibiotic. The genome also carries numerous sets of genes for the biosynthesis of diverse secondary metabolites.
GENOME ANNOUNCEMENT
Streptomyces globisporus C-1027, isolated from a soil sample collected in the Qian-jiang area of China (2), produces an extremely potent antitumor antibiotic, C-1027. As a member of enediyne family, C-1027 is currently undergoing phase II clinical trial in China (8). Here, we present a draft genome sequence of S. globisporus C-1027.
The nucleotide sequencing was performed by BGI (Shenzhen, China) using an illumina/GA sequencer. Short reads were assembled by SOAP de novo (3), and protein coding sequences (CDSs) were predicted by Glimmer, version 3.0 (1). Gene functional annotation was based on BLASTP results determined with the KEGG, COG, Swiss-Prot, NT, and NR databases. tRNA genes were predicted with tRNAscan-SE (7), and rRNA sequences were found by alignment with an rRNA pool.
A total of 1,242.47 Mb of data were generated, which represented 169.37-fold coverage of the genome. The draft genome sequence of S. globisporus C-1027 contains 7,693,617 bp with a GC content of 71.63% distributed over 84 scaffolds containing 278 contigs. We identified 7,231 putative protein CDSs, accounting for 88.22% of the genome, as well as 56 tRNA genes and five rRNA operons in our draft genome. The intact biosynthetic gene cluster for C-1027, which had been cloned and sequenced previously (4), was located on scaffold 34, with 99% identity to the sequence of the reported C-1027 biosynthetic genes. In addition, scaffold 34 disclosed a further 6,264 bp upstream of the C-1027 gene cluster in which a pair of genes composing a primase/helicase-like gene and a putative replication initiation gene were predicted. Together with three other pairs of these genes previously annotated adjacent to the C-1027 gene cluster, there are a total of four pairs of genes involved in the linear plasmid replication. The coding proteins of these genes are highly homologous to the plasmid-type DNA primase/replication proteins of plasmid pSLA2-L from S. rochei (5) and plasmid SCP1 from S. coelicolor (6), suggesting that the biosynthetic gene cluster of C-1027 is possibly located on a giant linear plasmid at least 92 kb in length. Genome analysis also revealed a number of genes related to biosynthesis of diverse secondary metabolites besides C-1027, including putative nonribosomal peptide synthetase (NRPS) genes, polyketide synthase (PKS) genes, NRPS-PKS hybrid genes, terpene cyclase genes, and genes for lantibiotic biosynthesis. The genome sequence of S. globisporus C-1027 will aid our further analysis and understanding of C-1027 biosynthesis-regulatory mechanisms and discovery of new natural products by uncovering cryptic metabolic pathways.
Nucleotide sequence accession numbers.
This whole-genome shotgun project has been deposited at DDBJ/EMBL/GenBank under accession no. AJUO00000000. The version described in this paper is the first version, deposited under AJUO01000000.
ACKNOWLEDGMENTS
We thank BGI (Shenzhen, China) for Solexa shotgun sequencing, assembly, and annotation of the genome.
This work was supported by the National Natural Science Foundation of China (31170042 and 30973668), Ministry of Science and Technology of China (2012ZX09301002-001-016, 2009ZX09501-008, and 2010ZX09401-403), and Beijing Natural Science Foundation (5102032).
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