Internal ribosome entry site (IRES)-dependent translation is a mechanism distinct from 5′ cap-dependent translation. IRES elements are located mainly in the 5′ untranslated regions (UTRs) of viral and eukaryotic mRNAs. However, IRESs are also found in the coding regions of some viral and eukaryotic genomes to initiate the translation of some functional truncated isoforms. Here, five putative IRES elements of human rhinovirus 16 (HRV16) were identified in the coding region of the nonstructural proteins P2 and P3 through fusion with green fluorescent protein (GFP) expression vectors and bicistronic vectors with a hairpin structure. These five putative IRESs were located at nucleotide positions 4286-4585, 5002-5126, 6245-6394, 6619-6718, and 6629-6778 in the HRV16 genome. The functionality of the five IRESs was confirmed by their ability to initiate GFP expression in vitro. This suggests that an alternative mechanism might be used to increase the efficiency of replication of HRV16.

内部核糖体进入位点 (IRES) 依赖性翻译是一种不同于 5' 帽依赖性翻译的机制。IRES 元件主要位于病毒和真核生物 mRNA 的 5' 非翻译区 (UTR)。然而，在一些病毒和真核基因组的编码区也发现了 IRES，以启动一些功能性截短同种型的翻译。在这里，通过与绿色荧光蛋白 (GFP) 表达载体和具有发夹结构的双顺反子载体融合，在非结构蛋白 P2 和 P3 的编码区鉴定了五个推定的人鼻病毒 16 (HRV16) IRES 元件。这五个推定的 IRES 位于 HRV16 基因组中的核苷酸位置 4286-4585、5002-5126、6245-6394、6619-6718 和 6629-6778。体外。这表明可以使用另一种机制来提高 HRV16 的复制效率。