Sofia H J, Burland V, Daniels D L, Plunkett G, Blattner F R
Laboratory of Genetics, University of Wisconsin, Madison 53706.
Nucleic Acids Res. 1994 Jul 11;22(13):2576-86. doi: 10.1093/nar/22.13.2576.
The DNA sequence of a 225.4 kilobase segment of the Escherichia coli K-12 genome is described here, from 76.0 to 81.5 minutes on the genetic map. This brings the total of contiguous sequence from the E.coli genome project to 725.1 kb (76.0 to 92.8 minutes). We found 191 putative coding genes (ORFs) of which 72 genes were previously known, and 110 of which remain unidentified despite literature and similarity searches. Seven new genes--arsE, arsF, arsG, treF, xylR, xylG, and xylH--were identified as well as the previously mapped pit and dctA genes. The arrangement of proposed genes relative to possible promoters and terminators suggests 90 potential transcription units. Other features include 19 REP elements, 95 computer-predicted bends, 50 Chi sites, and one grey hole. Thirty-one putative signal peptides were found, including those of thirteen known membrane or periplasmic proteins. One tRNA gene (proK) and two insertion sequences (IS5 and IS150) are located in this segment. The genes in this region are organized with equal numbers oriented with or against replication.
本文描述了大肠杆菌K-12基因组中一段225.4千碱基片段的DNA序列，该片段位于遗传图谱上76.0至81.5分钟处。这使得来自大肠杆菌基因组计划的连续序列总数达到725.1 kb（76.0至92.8分钟）。我们发现了191个推定的编码基因（开放阅读框），其中72个基因先前已为人所知，尽管经过文献检索和相似性搜索，仍有110个基因身份不明。鉴定出了7个新基因——arsE、arsF、arsG、treF、xylR、xylG和xylH——以及先前已定位的pit和dctA基因。推测基因相对于可能的启动子和终止子的排列表明有90个潜在的转录单元。其他特征包括19个重复元件、95个计算机预测的弯曲、50个Chi位点和1个灰洞。发现了31个推定的信号肽，包括13种已知膜蛋白或周质蛋白的信号肽。该片段中定位了1个tRNA基因（proK）和2个插入序列（IS5和IS150）。该区域的基因以与复制方向相同或相反的数量相等的方式排列。
