Systematic sequencing of the Escherichia coli genome

大肠杆菌K-12菌株的基因组由一个4700千碱基（kb）的环状DNA分子组成，其中估计存在约4000个基因。在预设，2,300 kb核苷酸序列的总数已被片段分析。在此之前，我们已经确定了对应于染色体0-6分钟区域的连续274 kb的核苷酸序列。利用Kohara的有序克隆，我们的测序工作已经扩展到12分钟区域。在这个项目中，我们一共新确定了149188 bp。将该序列与已知序列相结合，共测序了274 kb中226 kb（82.5%）的6-12 min区域。新序列经分析鉴定出86个潜在的开放阅读框，其氨基酸序列与其他已报道的序列具有显著的相似性。该序列还包含至少5个IS元件和2种独特的重复序列，分别由3x-和5x-93 bp组成。

The genome of Escherichia coli strain K-12 consists of a circular DNA molecule of 4,700 kilobases (kb), in which about 4,000 genes have been estimated to be present. At preset, 2,300-kb nucleotide sequences in sum have fragmentally been analyzed. Previously, we have determined the nucleotide sequence of a contiguous 274 kb corresponding to the 0-6 min region of the chromosome. Using the orderd clones of Kohara, our sequencing efforts have being extended to the 12 min region. In this project, we have determined newly a total of 149,188 bp. Combination of this sequence and the known sequences indicates that sequencing of 226 out of the 274 kb(82.5%) in the 6-12 min region has been completed. Analysis of the new sequence identified 86 potential open reading frames, whose amino acid sequences showed significant similarity to other reported sequences. The sequence also contains at least 5 IS elements and 2 types of unique repetitive sequences consisting of 3x- and 5x-93 bp, respectively.