Leclerc G, Noël G, Drapeau G R
Department of Microbiology and Immunology, Université de Montréal, Québec, Canada.
J Bacteriol. 1990 Aug;172(8):4696-700. doi: 10.1128/jb.172.8.4696-4700.1990.
Cells of Escherichia coli that harbor supH (an allele of the wild-type gene serU) are sensitive to UV irradiation and temperature and appear to have an impaired cell division control mechanism. We found that a gene located at the 2-min region, designated shl, inhibited the growth of supH-harboring cells when carried by a high-copy-number plasmid, whereas the same plasmid had no visible effect when present in parental cells. The amino acid sequence predicted from the nucleotide sequence of the shl gene indicated a similarity to the GalR and LacI repressor proteins, suggesting it is a transcription regulator. The sequence between the promoter and the structural genes revealed the presence of a short open reading frame of 28 amino acid residues followed by a segment of 81 base pairs. These structural features suggest that a transcription antitermination mechanism may be involved in the regulation of expression of the shl gene. The possibility that shl is a regulator of serU is discussed.
携带supH（野生型基因serU的一个等位基因）的大肠杆菌细胞对紫外线照射和温度敏感，并且似乎具有受损的细胞分裂控制机制。我们发现，位于2分钟区域的一个名为shl的基因，当由高拷贝数质粒携带时，会抑制携带supH的细胞的生长，而相同的质粒存在于亲本细胞中时则没有明显影响。从shl基因的核苷酸序列预测的氨基酸序列显示与GalR和LacI阻遏蛋白相似，表明它是一种转录调节因子。启动子和结构基因之间的序列显示存在一个由28个氨基酸残基组成的短开放阅读框，后面跟着一段81个碱基对的片段。这些结构特征表明转录抗终止机制可能参与了shl基因表达的调控。本文讨论了shl是serU调节因子的可能性。
