Krinke L, Wulff D L
Department of Biological Sciences, State University of New York, Albany 12222.
Nucleic Acids Res. 1990 Aug 25;18(16):4809-15. doi: 10.1093/nar/18.16.4809.
We determined sites in lambda cII mRNA that are cleaved by RNase III in the presence of lambda OOP antisense RNA, using a series of OOP RNAs with different internal deletions. In OOP RNA-cII mRNA structures containing a potential region of continuous double-stranded RNA bounded by a non-complementary unpaired region, RNase III cleaved the cII mRNA at one or more preferred sites located 10 to 14 bases from the 3'-end of the region of continuous complementarity. Cleavage patterns were almost identical when the presumptive structure was the same continuously double-stranded region followed by a single-stranded bulge and a second short region of base pairing. The sequences of the new cleavage sites show generally good agreement with a consensus sequence derived from thirty-five previously determined cleavage sequences. In contrast, four 'non-sites' at which cleavage is never observed show poor agreement with this consensus sequence. We conclude that RNase III specificity is determined both by the distance from the end of continuous pairing and by nucleotide sequence features within the region of pairing.
我们使用一系列具有不同内部缺失的OOP RNA，确定了在λ OOP反义RNA存在下被RNase III切割的λ cII mRNA中的位点。在包含由非互补未配对区域界定的潜在连续双链RNA区域的OOP RNA-cII mRNA结构中，RNase III在距连续互补区域3'端10至14个碱基处的一个或多个优选位点切割cII mRNA。当假定结构是相同的连续双链区域，随后是单链凸起和第二个短碱基配对区域时，切割模式几乎相同。新切割位点的序列与从先前确定的35个切割序列推导的共有序列总体上吻合良好。相比之下，从未观察到切割的四个“非位点”与该共有序列的吻合度较差。我们得出结论，RNase III的特异性既由距连续配对末端的距离决定，也由配对区域内的核苷酸序列特征决定。
