Kaneko T, Nakamura Y, Wolk C P, Kuritz T, Sasamoto S, Watanabe A, Iriguchi M, Ishikawa A, Kawashima K, Kimura T, Kishida Y, Kohara M, Matsumoto M, Matsuno A, Muraki A, Nakazaki N, Shimpo S, Sugimoto M, Takazawa M, Yamada M, Yasuda M, Tabata S
Kazusa DNA Research Institute, Kisarazu, Chiba, Japan.
DNA Res. 2001 Oct 31;8(5):205-13; 227-53. doi: 10.1093/dnares/8.5.205.
The nucleotide sequence of the entire genome of a filamentous cyanobacterium, Anabaena sp. strain PCC 7120, was determined. The genome of Anabaena consisted of a single chromosome (6,413,771 bp) and six plasmids, designated pCC7120alpha (408,101 bp), pCC7120beta (186,614 bp), pCC7120gamma (101,965 bp), pCC7120delta (55,414 bp), pCC7120epsilon (40,340 bp), and pCC7120zeta (5,584 bp). The chromosome bears 5368 potential protein-encoding genes, four sets of rRNA genes, 48 tRNA genes representing 42 tRNA species, and 4 genes for small structural RNAs. The predicted products of 45% of the potential protein-encoding genes showed sequence similarity to known and predicted proteins of known function, and 27% to translated products of hypothetical genes. The remaining 28% lacked significant similarity to genes for known and predicted proteins in the public DNA databases. More than 60 genes involved in various processes of heterocyst formation and nitrogen fixation were assigned to the chromosome based on their similarity to the reported genes. One hundred and ninety-five genes coding for components of two-component signal transduction systems, nearly 2.5 times as many as those in Synechocystis sp. PCC 6803, were identified on the chromosome. Only 37% of the Anabaena genes showed significant sequence similarity to those of Synechocystis, indicating a high degree of divergence of the gene information between the two cyanobacterial strains.
测定了丝状蓝细菌鱼腥藻Anabaena sp. 菌株PCC 7120的全基因组核苷酸序列。鱼腥藻的基因组由一条染色体（6,413,771 bp）和6个质粒组成，分别命名为pCC7120α（408,101 bp）、pCC7120β（186,614 bp）、pCC7120γ（101,965 bp）、pCC7120δ（55,414 bp）、pCC7120ε（40,340 bp）和pCC7120ζ（5,584 bp）。该染色体含有5368个潜在的蛋白质编码基因、4套rRNA基因、代表42种tRNA种类的48个tRNA基因以及4个小结构RNA基因。45%的潜在蛋白质编码基因的预测产物与已知功能的已知和预测蛋白质具有序列相似性，27%与假定基因的翻译产物具有相似性。其余28%与公共DNA数据库中已知和预测蛋白质的基因缺乏显著相似性。基于与已报道基因的相似性，超过60个参与异形胞形成和固氮各种过程的基因被定位到该染色体上。在该染色体上鉴定出195个编码双组分信号转导系统组分的基因，几乎是集胞藻Synechocystis sp. PCC 6803中此类基因数量的2.5倍。鱼腥藻只有37%的基因与集胞藻的基因具有显著的序列相似性，这表明这两种蓝细菌菌株之间的基因信息存在高度差异。
