Chuang S E, Blattner F R
Laboratory of Genetics, University of Wisconsin-Madison 53706.
J Bacteriol. 1993 Aug;175(16):5242-52. doi: 10.1128/jb.175.16.5242-5252.1993.
Most organisms respond to heat by substantial alteration of the pattern of gene expression. This has been particularly well studied with Escherichia coli although the response has by no means been completely characterized. Here we report the characterization of 26 new heat shock genes of E. coli, termed hsl, discovered by global transcription analysis with an overlapping lambda clone bank. We have measured the molecular weights of the corresponding heat shock proteins and mapped each of them to within a few kilobases on the E. coli genome. In vitro, 16 of them can be activated by the E sigma 32 RNA polymerase, which specifically transcribes heat shock genes. In vivo expression kinetics of seven of eight examined new proteins were found to be similar to those of the four most studied heat shock proteins, DnaK, DnaJ, GroEL (MopA), and GroES (MopB). In the course of this work, we confirmed that the catalytic subunit of the ATP-dependent Clp protease (also known as Ti protease), ClpP, is derived from a larger precursor protein. Possible assignments of some of the hsl genes to known proteins are discussed.
大多数生物体通过基因表达模式的显著改变来应对热刺激。这一点在大肠杆菌中得到了特别深入的研究，尽管其应答机制尚未完全明确。在此，我们报告了通过使用重叠λ克隆文库进行全基因组转录分析发现的26个大肠杆菌新热休克基因（称为hsl）的特性。我们测定了相应热休克蛋白的分子量，并将它们各自定位在大肠杆菌基因组上的几千碱基范围内。在体外，其中16个基因可被特异性转录热休克基因的E σ32 RNA聚合酶激活。在所检测的8种新蛋白中，有7种的体内表达动力学被发现与研究最多的4种热休克蛋白DnaK、DnaJ、GroEL（MopA）和GroES（MopB）相似。在这项工作过程中，我们证实了ATP依赖性Clp蛋白酶（也称为Ti蛋白酶）的催化亚基ClpP源自一种更大的前体蛋白。文中还讨论了一些hsl基因与已知蛋白的可能对应关系。
