SEQUENCE-ANALYSIS OF 4 NEW HEAT-SHOCK GENES CONSTITUTING THE HSLTS IBPAB AND HSLVU OPERONS IN ESCHERICHIA-COLI
SEQUENCE-ANALYSIS OF 4 NEW HEAT-SHOCK GENES CONSTITUTING THE HSLTS IBPAB AND HSLVU OPERONS IN ESCHERICHIA-COLI
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DOI：
10.1016/0378-1119(93)90167-2
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发表时间：
1993-11-30
期刊：
影响因子：
3.5
通讯作者：
BLATTNER, FR
中科院分区：
文献类型：
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作者：
CHUANG, SE;BURLAND, V;BLATTNER, FR
测定了大肠杆菌热休克（HS）新基因的两个操纵子序列。83 min时，该操纵子指定了两个蛋白，分别为15.8 kDa （HslT）和16.1 kDa (HslS)，与IbpA和IbpB相同。当温度升高时，hslTS/ibpAB操纵子的sigma32依赖启动子的mRNA表达被刺激30-75倍。转录起始点（tsp）位于hslT/ibpA的AUG起始密码子上游96 bp处。HslT/IbpA和HslS/IbpB的氨基酸序列同源性为48%，与叶绿体低分子HS蛋白有较远的亲缘关系，该蛋白在植物中具有高度保守性。第二个hs操纵子受温度升高的刺激要小得多，尽管它有一个hs启动子，完全符合sigma32识别的启动子共识。hslVU操纵子位于88.9分钟，指定19.1 kDa （HslV）和49.6 kDa （Hs]U）的蛋白。在该操纵子中发现了多个tsp。HslV与真核生物蛋白酶体蛋白有较远的亲缘关系，HslU与功能未知的溶血巴斯德杆菌蛋白非常相似。HslU和溶血疟原虫蛋白在其n端附近都有一个ATP/ gtp结合基序。这里描述的两个操纵子在标准基因图谱上是逆时针转录的。
Sequences of four new heat-shock (HS) genes of Escherichia coli organized into two operons were determined. The operon at 83 min specifies two proteins of 15.8 kDa (HslT) and 16.1 kDa (HslS), which are identical to IbpA and IbpB, respectively. Expression of mRNA from a sigma32-dependent promoter of the hslTS/ibpAB operon is stimulated 30-75-fold upon temperature upshift. The transcription start point (tsp) is located at a G, 96 bp upstream from the AUG start codon of hslT/ibpA. The deduced amino acid sequences of HslT/IbpA and HslS/IbpB are 48% identical to each other and were found to be remotely related to the chloroplast low-molecular-weight HS protein, which is highly conserved among plants. The second hs operon is much less actively stimulated by temperature upshift, although it has a hs promoter that perfectly matches the consensus of promoters recognized by sigma32. Located at 88.9 min, the hslVU operon specifies proteins of 19.1 kDa (HslV) and 49.6 kDa (Hs]U). Multiple tsp were found in this operon. HslV is remotely related to the eukaryotic proteasome proteins, and HslU is very similar to a Pasteurella haemolytica protein of unknown function. Both HslU and the P. haemolytica protein share a ATP/GTP-binding motif near their N-termini. The two operons described here are transcribed counterclockwise on the standard genetic map.