Wang W, Bechhofer D H
Department of Biochemistry, Mount Sinai School of Medicine of the City University of New York, New York 10029, USA.
J Bacteriol. 1997 Dec;179(23):7379-85. doi: 10.1128/jb.179.23.7379-7385.1997.
The rnc gene of Bacillus subtilis, which has 36% amino acid identity with the gene that encodes Escherichia coli RNase III endonuclease, was cloned in E. coli and shown by functional assays to encode B. subtilis RNase III (Bs-RNase III). The cloned B. subtilis rnc gene could complement an E. coli rnc strain that is deficient in rRNA processing, suggesting that Bs-RNase III is involved in rRNA processing in B. subtilis. Attempts to construct a B. subtilis rnc null mutant were unsuccessful, but a strain was constructed in which only a carboxy-terminal truncated version of Bs-RNase III was expressed. The truncated Bs-RNase III showed virtually no activity in vitro but was active in vivo. Analysis of expression of a copy of the rnc gene integrated at the amy locus and transcribed from a p(spac) promoter suggested that expression of the B. subtilis rnc is under regulatory control.
枯草芽孢杆菌的rnc基因与编码大肠杆菌核糖核酸酶III内切核酸酶的基因具有36%的氨基酸同一性，该基因在大肠杆菌中克隆，并通过功能测定表明其编码枯草芽孢杆菌核糖核酸酶III（Bs - 核糖核酸酶III）。克隆的枯草芽孢杆菌rnc基因可以补充rRNA加工缺陷的大肠杆菌rnc菌株，这表明Bs - 核糖核酸酶III参与枯草芽孢杆菌的rRNA加工。构建枯草芽孢杆菌rnc缺失突变体的尝试未成功，但构建了一个仅表达Bs - 核糖核酸酶III羧基末端截短版本的菌株。截短的Bs - 核糖核酸酶III在体外几乎没有活性，但在体内有活性。对整合在amy位点并从p（spac）启动子转录的rnc基因拷贝的表达分析表明，枯草芽孢杆菌rnc的表达受调控控制。
