Complete genome structure of the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1

• Published in: DNA research 2002, Vol.9 (4), p.123-130
• Main Authors: NAKAMURA, Yasukazu, KANEKO, Takakazu, KISHIDA, Yoshie, KIYOKAWA, Chiaki, KOHARA, Mitsuyo, MATSUMOTO, Midori, MATSUNO, Ai, NAKAZAKI, Naomi, SHIMPO, Sayaka, SUGIMOTO, Masako, TAKEUCHI, Chie, YAMADA, Manabu, SATO, Shusei, TABATA, Satoshi, IKEUCHI, Masahiko, KATOH, Hiroshi, SASAMOTO, Shigemi, WATANABE, Akiko, IRIGUCHI, Mayumi, KAWASHIMA, Kumiko, KIMURA, Takaharu
• Format: Article
• Language: English
• Subjects: Anabaena; Biological and medical sciences; Cyanobacteria - genetics; Cyanobacteria - metabolism; Cyanophyta; Fundamental and applied biological sciences. Psychology; Genes. Genome; Genome, Bacterial; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Photosynthesis - genetics; Sequence Analysis, DNA; Synechocystis; Thermosynechococcus elongatus
• ISSN: 1340-2838; 1756-1663
• DOI: 10.1093/dnares/9.4.123

The entire genome of a thermophilic unicellular cyanobacterium, Thermosynechococcus elongatus BP-1, was sequenced. The genome consisted of a circular chromosome 2,593,857 bp long, and no plasmid was detected. A total of 2475 potential protein-encoding genes, one set of rRNA genes, 42 tRNA genes representing 42 tRNA species and 4 genes for small structural RNAs were assigned to the chromosome by similarity search and computer prediction. The translated products of 56% of the potential protein-encoding genes showed sequence similarity to experimentally identified and predicted proteins of known function, and the products of 34% of these genes showed sequence similarity to the translated products of hypothetical genes. The remaining 10% lacked significant similarity to genes for predicted proteins in the public DNA databases. Sixty-three percent of the T. elongatus genes showed significant sequence similarity to those of both Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120, while 22% of the genes were unique to this species, indicating a high degree of divergence of the gene information among cyanobacterial strains. The lack of genes for typical fatty acid desaturases and the presence of more genes for heat-shock proteins in comparison with other mesophilic cyanobacteria may be genomic features of thermophilic strains. A remarkable feature of the genome is the presence of 28 copies of group II introns, 8 of which contained a presumptive gene for maturase/reverse transcriptase. A trace of genome rearrangement mediated by the group II introns was also observed.