The structure and mechanism of action of a distinct class of dicistrovirus intergenic region IRESs.
The structure and mechanism of action of a distinct class of dicistrovirus intergenic region IRESs.
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DOI：
10.1093/nar/gkad569
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发表时间：
2023-09-22
影响因子：
14.9
通讯作者：
Hellen, Christopher U. T.
中科院分区：
文献类型：
--
作者：
Abaeva, Irina S.;Young, Christina;Warsaba, Reid;Khan, Nadiyah;Tran, Lan Vy;Jan, Eric;Pestova, Tatyana, V;Hellen, Christopher U. T.
内部核糖体进入位点（IRESs）与真核翻译装置相互作用以促进不依赖于末端的起始。我们在来自节肢动物门、苔藓动物门、刺胞动物门、棘皮动物门、内肛动物门、软体动物门和多孔动物门成员的双顺反子病毒基因组中鉴定出一类约150个核苷酸长的保守基因间区域（IGR）IRESs。这些IRESs以温岭类小核糖核酸病毒2为例，类似于典型的蟋蟀麻痹病毒（CrPV）IGR IRES，包含两个嵌套的假结（PKII/PKIII）和一个3′末端假结（PKI），其模拟与信使核糖核酸（mRNA）碱基配对的转运核糖核酸（tRNA）反密码子茎环。然而，它们比类CrPV IRESs短约50个核苷酸，并且PKIII是一种H型假结，缺乏主要负责类CrPV IRESs对40S核糖体亚基亲和力以及限制PKI初始结合到其氨酰基（A）位点的SLIV和SLV茎环。温岭类IRESs与80S核糖体紧密结合，但与40S亚基结合较弱。类CrPV IRESs必须通过延伸因子2从A位点转移到肽酰基（P）位点才能开始延伸，而温岭类IRESs直接结合到80S核糖体的P位点，并且在没有预先转移步骤的情况下就开始解码。一个含有温岭类IRES的嵌合CrPV克隆具有感染性，证实了该IRES在细胞中发挥功能。
Internal ribosomal entry sites (IRESs) engage with the eukaryotic translation apparatus to promote end-independent initiation. We identified a conserved class of ∼150 nt long intergenic region (IGR) IRESs in dicistrovirus genomes derived from members of the phyla Arthropoda, Bryozoa, Cnidaria, Echinodermata, Entoprocta, Mollusca and Porifera. These IRESs, exemplified by Wenling picorna-like virus 2, resemble the canonical cricket paralysis virus (CrPV) IGR IRES in comprising two nested pseudoknots (PKII/PKIII) and a 3′-terminal pseudoknot (PKI) that mimics a tRNA anticodon stem–loop base-paired to mRNA. However, they are ∼50 nt shorter than CrPV-like IRESs, and PKIII is an H-type pseudoknot that lacks the SLIV and SLV stem–loops that are primarily responsible for the affinity of CrPV-like IRESs for the 40S ribosomal subunit and that restrict initial binding of PKI to its aminoacyl (A) site. Wenling-class IRESs bound strongly to 80S ribosomes but only weakly to 40S subunits. Whereas CrPV-like IRESs must be translocated from the A site to the peptidyl (P) site by elongation factor 2 for elongation to commence, Wenling-class IRESs bound directly to the P site of 80S ribosomes, and decoding begins without a prior translocation step. A chimeric CrPV clone containing a Wenling-class IRES was infectious, confirming that the IRES functioned in cells.
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影响因子：
14.9
作者：
Nishiyama T;Yamamoto H;Uchiumi T;Nakashima N
通讯作者：
Nakashima N
DOI：
10.3390/v12111332
发表时间：
2020-11-20
期刊：
Viruses
影响因子：
--
作者：
Hewson I;Aquino CA;DeRito CM
通讯作者：
DeRito CM
影响因子：
64.5
作者：
Alkalaeva, Elena Z.;Pisarev, Andrey V.;Pestova, Tatyana V.
通讯作者：
Pestova, Tatyana V.
影响因子：
11.4
作者：
Brown, Zuben P.;Abaeva, Irina S.;Frank, Joachim
通讯作者：
Frank, Joachim
影响因子：
4.5
作者：
Costantino, D;Kieft, JS
通讯作者：
Kieft, JS