Secondary Structure of a Conserved Domain in the Intron of Influenza A NS1 mRNA

Influenza A virus is a segmented single-stranded (−)RNA virus that causes substantial annual morbidity and mortality. The transcriptome of influenza A is predicted to have extensive RNA secondary structure. The smallest genome segment, segment 8, encodes two proteins, NS1 and NEP, via alternative splicing. A conserved RNA domain in the intron of segment 8 may be important for regulating production of NS1. Two different multi-branch loop structures have been proposed for this region. A combination of in vitro chemical mapping and isoenergetic microarray techniques demonstrate that the consensus sequence for this region folds into a hairpin conformation. These results provide an alternative folding for this region and a foundation for designing experiments to probe its functional role in the influenza life cycle.甲型流感病毒（Influenza A virus）为分节段单链负链RNA病毒，每年可造成显著的发病与死亡负担。甲型流感病毒的转录组被预测存在大量RNA二级结构。其最小的基因组节段——第8节段——通过可变剪接编码NS1与NEP两种蛋白。第8节段内含子中的保守RNA结构域，对调控NS1的表达可能具有重要作用。针对该区域，已有研究提出两种不同的多分支环结构模型。结合体外化学作图与等能量微阵列技术，研究证实该区域的保守序列可折叠形成发夹构象。本研究结果为该区域提供了一种替代折叠模型，并为设计实验探究其在流感病毒生命周期中的功能角色奠定了基础。