title: Complete genomic structure of the bloom-forming toxic cyanobacterium Microcystis aeruginosa NIES-843.
abstract: The nucleotide sequence of the complete genome of a cyanobacterium, Microcystis aeruginosa NIES-843, was determined. The genome of M. aeruginosa is a single, circular chromosome of 5,842,795 base pairs (bp) in length, with an average GC content of 42.3%. The chromosome comprises 6312 putative protein-encoding genes, two sets of rRNA genes, 42 tRNA genes representing 41 tRNA species, and genes for tmRNA, the B subunit of RNase P, SRP RNA, and 6Sa RNA. Forty-five percent of the putative protein-encoding sequences showed sequence similarity to genes of known function, 32% were similar to hypothetical genes, and the remaining 23% had no apparent similarity to reported genes. A total of 688 kb of the genome, equivalent to 11.8% of the entire genome, were composed of both insertion sequences and miniature inverted-repeat transposable elements. This is indicative of a plasticity of the M. aeruginosa genome, through a mechanism that involves homologous recombination mediated by repetitive DNA elements. In addition to known gene clusters related to the synthesis of microcystin and cyanopeptolin, novel gene clusters that may be involved in the synthesis and modification of toxic small polypeptides were identified. Compared with other cyanobacteria, a relatively small number of genes for two component systems and a large number of genes for restriction-modification systems were notable characteristics of the M. aeruginosa genome.
authors.affiliation: Kazusa DNA Research Institute, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan. kaneko@kazusa.or.jp
authors.forename: Takakazu
authors.initials: T
authors.lastname: Kaneko
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Nakajima
authors.forename: Shinobu
authors.initials: S
authors.lastname: Okamoto
authors.forename: Iwane
authors.initials: I
authors.lastname: Suzuki
authors.forename: Yuuhiko
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Masanori
authors.initials: M
authors.lastname: Tamaoki
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Fumie
authors.initials: F
authors.lastname: Kasai
authors.forename: Akiko
authors.initials: A
authors.lastname: Watanabe
authors.forename: Kumiko
authors.initials: K
authors.lastname: Kawashima
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Kishida
authors.forename: Akiko
authors.initials: A
authors.lastname: Ono
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Chika
authors.initials: C
authors.lastname: Takahashi
authors.forename: Chiharu
authors.initials: C
authors.lastname: Minami
authors.forename: Tsunakazu
authors.initials: T
authors.lastname: Fujishiro
authors.forename: Mitsuyo
authors.initials: M
authors.lastname: Kohara
authors.forename: Midori
authors.initials: M
authors.lastname: Katoh
authors.forename: Naomi
authors.initials: N
authors.lastname: Nakazaki
authors.forename: Shinobu
authors.initials: S
authors.lastname: Nakayama
authors.forename: Manabu
authors.initials: M
authors.lastname: Yamada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Makoto M
authors.initials: MM
authors.lastname: Watanabe
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001482:Base Composition; D001483:Base Sequence; D016680:Genome, Bacterial / Q000235:genetics*; D046931:Microcystis / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins