Eukaryotic ribosomal protein RPS25 interacts with the conserved loop region in a dicistroviral intergenic internal ribosome entry site.
Eukaryotic ribosomal protein RPS25 interacts with the conserved loop region in a dicistroviral intergenic internal ribosome entry site.
复制标题
DOI：
10.1093/nar/gkl1121
复制
发表时间：
2007
影响因子：
14.9
通讯作者：
Nakashima N
中科院分区：
文献类型：
--
作者：
Nishiyama T;Yamamoto H;Uchiumi T;Nakashima N
在缺乏真核细胞起始因子(EIF)的情况下，双胞菌病毒的基因间区-内部核糖体进入位点(IGR-IRES)与40S核糖体亚基结合。虽然双轮病毒IGR-IRES元件中保守的环序列在40S亚基的存在下不受化学修饰，但40S亚基中与IRES中的环序列相互作用的分子成分尚未被鉴定。在这里，使用4-硫代尿苷标记的IGR-IRES的化学交联研究揭示了IGR-IRES与几个40S蛋白质的相互作用，但不与18S rRNA相互作用。核糖体蛋白S25(RpS25)是最强的交联信号。已知rpS25是rpS5的邻居，冷冻电子显微镜表明rpS5与相关的IGR-IRES相互作用。定点突变的交联分析表明，位于IRES保守结构域2b环区的核苷酸UU6089-6090似乎与rpS25相互作用。RpS25是真核生物特有的，这解释了为什么原核糖体不识别IGR-IRES。虽然已经推测IGR-IRES元件可能是原始翻译系统的残留物，但我们的实验数据表明IRES已经适应了真核核糖体蛋白。
The intergenic region-internal ribosome entry site (IGR-IRES) of dicistroviruses binds to 40S ribosomal subunits in the absence of eukaryotic initiation factors (eIFs). Although the conserved loop sequences in dicistroviral IGR-IRES elements are protected from chemical modifications in the presence of the 40S subunit, molecular components in the 40S subunit, which interacts with the loop sequences in the IRES, have not been identified. Here, a chemical crosslinking study using 4-thiouridine-labeled IGR-IRES revealed interactions of the IGR-IRES with several 40S proteins but not with the 18S rRNA. The strongest crosslinking signal was identified for ribosomal protein S25 (rpS25). rpS25 is known to be a neighbor of rpS5, which has been shown to interact with a related IGR-IRES by cryo-electron microscopy. Crosslinking analysis with site-directed mutants showed that nucleotides UU6089–6090, which are located in the loop region in conserved domain 2b in the IRES, appear to interact with rpS25. rpS25 is specific to eukaryotes, which explains why there is no recognition of the IGR-IRES by prokaryotic ribosomes. Although the idea that the IGR-IRES element may be a relict of a primitive translation system has been postulated, our experimental data suggest that the IRES has adapted to eukaryotic ribosomal proteins.
登录
查看更多内容
影响因子：
2.9
作者：
BRADFORD, CT;SULLIVAN, DT
通讯作者：
SULLIVAN, DT
影响因子：
1.7
作者：
Lehto, Kirsi;Karetnikov, Alexey
通讯作者：
Karetnikov, Alexey
影响因子：
14.9
作者：
Nishiyama, T;Yamamoto, H;Nakashima, N
通讯作者：
Nakashima, N
影响因子：
4.8
作者：
Fukushi, S;Okada, M;Katayama, K
通讯作者：
Katayama, K
影响因子：
56.9
作者：
Pfingsten, Jennifer S.;Costantino, David A.;Kieft, Jeffrey S.
通讯作者：
Kieft, Jeffrey S.