Nejman-Faleńczyk Bożena, Bloch Sylwia, Licznerska Katarzyna, Dydecka Aleksandra, Felczykowska Agnieszka, Topka Gracja, Węgrzyn Alicja, Węgrzyn Grzegorz
Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland.
Laboratory of Molecular Biology (affiliated with the University of Gdansk), Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Wita Stwosza 59, 80-308 Gdansk, Poland.
Sci Rep. 2015 May 11;5:10080. doi: 10.1038/srep10080.
A microRNA-size (20-nt long) molecule has been identified in Escherichia coli after induction of Shiga toxin-converting bacteriophage Φ24B. This small RNA, named 24B_1, is encoded in the lom-vb_24B_43 region of the phage genome, and apparently it is produced by cleavage of a larger transcript. A phage devoid of 24B_1 revealed decreased efficiency of lysogenization, quicker prophage induction after provoking the SOS response, higher efficiency of progeny phage production during the lytic cycle and less efficient adsorption on the host cells. Expression of most of phage genes was drastically increased after infection of E. coli by the Φ24BΔ24B_1 phage. Since 24B_1 may impair expression of the d_ant gene, coding for an anti-repressor, these results may explain the mechanism of regulations of the physiological processes by this small RNA due to impaired activity of the cI repressor and changed expression of vast majority of phage genes. To our knowledge, this is the first example of functional microRNA-size molecule in bacterial cells.
在诱导志贺毒素转化噬菌体Φ24B后，在大肠杆菌中鉴定出一种微小RNA大小（20个核苷酸长）的分子。这种小RNA名为24B_1，编码于噬菌体基因组的lom-vb_24B_43区域，显然它是由一个较大转录本的切割产生的。缺失24B_1的噬菌体显示出溶原化效率降低、引发SOS反应后前噬菌体诱导更快、裂解周期中后代噬菌体产生效率更高以及对宿主细胞的吸附效率更低。在大肠杆菌被Φ24BΔ24B_1噬菌体感染后，大多数噬菌体基因的表达急剧增加。由于24B_1可能损害编码抗阻遏物的d_ant基因的表达，这些结果可能解释了这种小RNA通过损害cI阻遏物的活性和改变绝大多数噬菌体基因的表达来调节生理过程的机制。据我们所知，这是细菌细胞中功能性微小RNA大小分子的第一个例子。
