McDowall K J, Cohen S N
Department of Genetics, Stanford University School of Medicine, Stanford University, CA 94305, USA.
J Mol Biol. 1996 Jan 26;255(3):349-55. doi: 10.1006/jmbi.1996.0027.
The rne gene of Escherichia coli encodes a 118 kDa protein that has ribonuclease E (RNase E) activity and binds RNA. A functional rne gene product is essential for cell viability and for the processing and/or decay of a variety of RNA species, including 9 S RNA, mRNA and RNAI, the antisense RNA regulator of ColE1-type plasmid replication. By testing the ability of different segments of the Rne protein to catalyze RNA cleavage and to bind RNA, we found that the N-terminal half (residues 1 to 498) of Rne contains a catalytic function sufficient for site-specific cleavage of oligoribonucleotides and complex RNAs. The C-terminal half of the protein, which contains both an arginine-rich region (residues 597 to 684) that we show binds RNA and a segment that is essential for cell viability (residues 844 to 1061), had no detectable endoribonucleolytic activity. Our results, which map the catalytic domain of RNase E, indicate the existence of discrete functional domains within the multifaceted Rne protein.
大肠杆菌的rne基因编码一种118 kDa的蛋白质，该蛋白质具有核糖核酸酶E（RNase E）活性并能结合RNA。功能性的rne基因产物对于细胞活力以及多种RNA种类（包括9 S RNA、mRNA和RNAI，即ColE1型质粒复制的反义RNA调节因子）的加工和/或降解至关重要。通过测试Rne蛋白不同片段催化RNA切割和结合RNA的能力，我们发现Rne的N端一半（第1至498位氨基酸残基）具有足以对寡核糖核苷酸和复杂RNA进行位点特异性切割的催化功能。该蛋白质的C端一半包含一个我们发现能结合RNA的富含精氨酸区域（第597至684位氨基酸残基）以及一个对细胞活力至关重要的片段（第844至1061位氨基酸残基），但没有可检测到的核糖核酸内切酶活性。我们绘制RNase E催化结构域的结果表明，多面的Rne蛋白中存在离散的功能结构域。
