Draft Genome Sequence of the Marine Streptomyces sp. Strain AA1529, Isolated from the Yellow Sea

Abstract

Here we report the draft genome sequence of a Streptomyces strain, AA1529, isolated from marine sediment from the Yellow Sea. Its genome contains a subset of unique genes and gene clusters that encode diverse secondary metabolites, suggesting great potential as a source for the discovery of novel gene clusters and bioactive compounds.

GENOME ANNOUNCEMENT

Streptomyces bacteria are remarkably rich sources of natural products (NPs), accounting for the production of over two-thirds of the commercially available antibiotics in current use (1). This genus still produces a larger number and variety of novel bioactive compounds than any other genus (12). In the course of our screening program for new NPs from marine microorganisms, Streptomyces sp. strain AA1529 was isolated from a marine sediment sample taken at a water depth of 50 m (35°12′125″N, 119°41′881″E) in the Yellow Sea close to Rizhao City, Shangdong Province, China. Its metabolites had good specific antitumor activity on a human ovarian carcinoma cell line, NIH:OVCAR-3. Here we reported the draft genome sequence of Streptomyces sp. strain AA1529.

Raw genome data were generated by a Roche 454 Genome Sequencer FLX and assembled using the GS de novo Assembler software. A total of 391,115 reads including up to 170.7 Mb were obtained, which represented 23.4-fold coverage of the genome. The Streptomyces sp. strain AA1529 draft genome was distributed into 109 contigs totaling 7,285,977 bp with an average GC content of 72.8%. Putative protein-encoding sequences were identified using Glimmer (2) and GeneMark (5). Functional annotation was based on BLASTP results with the KEGG and NR databases. tRNA and rRNA genes were predicted with tRNAscan-SE (10) and RNAmmer (4), respectively. The signal peptide cleavage sites, transmembrane topologies, and lipoproteins were predicted by SignalP 4.0 (7), TMHMM 2.0 (3), and LipoP 1.0 (8), respectively. The draft genome consisted of one linear chromosome with 5 rRNA operons, 58 tRNA genes, and 6,334 coding sequences (CDSs). For the CDSs, 4,235 proteins could be assigned to Clusters of Orthologous Groups families (9) and 576 CDSs encode proteins with no match to any known proteins in the current public databases, suggesting that the AA1529 genome is highly strain specific. As for the subcellular localization of the proteins, we identified 445 proteins as secreted proteins, 1,402 proteins as transmembrane proteins, and 301 proteins as transporters.

Twenty-three secondary-metabolite (2 siderophores, 3 terpenes, 2 lantibiotics, 6 polyketide synthases [PKS], 4 nonribosomal peptide synthetases [NRPS], and 6 hybrid NRPS-PKS) biosynthetic gene clusters were identified by antiSMASH (6). One hundred sixteen diverse secondary metabolic genes located in various gene clusters on the AA1529 genome were predicted by genome analysis, suggesting high genomic synteny to those of various Streptomyces species. Many putative genes involved in antibiotic biosynthesis showed low identity with the known ones, suggesting that AA1529 may be a potential producer of novel NPs. Additionally, some antimicrobial peptides predicted by the CAMP database (11) had significant DNA and amino acid sequence variations from their orthologs from other Streptomyces species. Thus, mining of the Streptomyces sp. strain AA1529 genome will further elucidate the chemical and genetic diversity of this strain for the discovery of novel gene clusters and bioactive compounds.

Nucleotide sequence accession numbers.

This whole-genome shotgun project has been deposited at DDBJ/EMBL/GenBank under accession no. ALAP00000000. The version described in this paper is the first version, ALAP01000000.