Truncaite Lidija, Zajanckauskaite Aurelija, Arlauskas Aivaras, Nivinskas Rimas
Department of Gene Engineering, Institute of Biochemistry, Mokslininku 12, 08662 Vilnius, Lithuania.
Virology. 2006 Jan 20;344(2):378-90. doi: 10.1016/j.virol.2005.09.001. Epub 2005 Oct 12.
Early gene expression in bacteriophage T4 is controlled primarily by the unique early promoters, while T4-encoded RegB endoribonuclease promotes degradation of many early messages contributing to the rapid shift of gene expression from the early to middle stages. The regulatory region for the genes clustered upstream of DNA ligase gene 30 of T4 was known to carry two strong early promoters and two putative RegB sites. Here, we present the comparative analysis of the regulatory events in this region of 16 T4-type bacteriophages. The regulatory elements for control of this gene cluster, such as rho-independent terminator, at least one early promoter, the sequence for stem-loop structure, and the RegB cleavage sites have been found to be conserved in the phages studied. Also, we present experimental evidence that the initial cleavage by RegB of phages TuIa and RB69 enables degradation of early phage mRNAs by the major Escherichia coli endoribonuclease, RNase E.
噬菌体T4的早期基因表达主要受独特的早期启动子控制，而T4编码的RegB核糖核酸内切酶促进许多早期信使RNA的降解，这有助于基因表达从早期快速转变为中期。已知T4 DNA连接酶基因30上游成簇基因的调控区域带有两个强早期启动子和两个假定的RegB位点。在此，我们对16种T4型噬菌体该区域的调控事件进行了比较分析。已发现控制该基因簇的调控元件，如不依赖ρ因子的终止子、至少一个早期启动子、茎环结构序列和RegB切割位点在所研究的噬菌体中是保守的。此外，我们提供了实验证据，表明噬菌体TuIa和RB69的RegB初始切割能使主要的大肠杆菌核糖核酸内切酶RNase E降解早期噬菌体信使RNA。
