Gitt M A, Wang L F, Doi R H
J Biol Chem. 1985 Jun 25;260(12):7178-85.
The Bacillus subtilis rpoD gene has been sequenced and the primary structure of its product deduced. The molecular weight calculated for the sigma 43 is 42,828. The DNA and protein sequences of sigma 43 exhibit extensive homology to the Escherichia coli rpoD gene and its sigma 70 product, especially in the C-terminal two-thirds of the sequence. Other proteins exhibiting partial homology with sigma 43 include the E. coli nusA protein, the E. coli htpR (heat-shock regulatory gene) product sigma 32, and specific DNA-binding proteins. No amino acid homology was found between sigma 43 and B. subtilis phage SP01 sigma gp28, phage T7 RNA polymerase, or E. coli DNA primase. The gene exhibits a strong ribosomal binding site and a typical rho-independent transcription terminator sequence. A typical transcription terminator sequence was not observed upstream from the sigma 43 gene. The sigma 43 gene may be part of an operon, resembling the situation found in the E. coli sigma operon.
枯草芽孢杆菌的rpoD基因已被测序，并推导了其产物的一级结构。计算得出的σ43的分子量为42,828。σ43的DNA和蛋白质序列与大肠杆菌的rpoD基因及其σ70产物表现出广泛的同源性，尤其是在序列的C端三分之二部分。与σ43表现出部分同源性的其他蛋白质包括大肠杆菌的nusA蛋白、大肠杆菌的htpR（热休克调节基因）产物σ32以及特定的DNA结合蛋白。在σ43与枯草芽孢杆菌噬菌体SP01的σgp28、噬菌体T7 RNA聚合酶或大肠杆菌DNA引发酶之间未发现氨基酸同源性。该基因具有一个强核糖体结合位点和一个典型的不依赖ρ因子的转录终止子序列。在σ43基因上游未观察到典型的转录终止子序列。σ43基因可能是一个操纵子的一部分，类似于在大肠杆菌σ操纵子中发现的情况。
