ArfA recognizes the lack of mRNA in the mRNA channel after RF2 binding for ribosome rescue.
ArfA recognizes the lack of mRNA in the mRNA channel after RF2 binding for ribosome rescue.
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DOI：
10.1093/nar/gku1069
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发表时间：
2014-12-01
影响因子：
14.9
通讯作者：
Himeno H
中科院分区：
文献类型：
--
作者：
Kurita D;Chadani Y;Muto A;Abo T;Himeno H
虽然tmRNA-SmpB介导的反式翻译长期以来一直被认为是唯一解救细菌停滞的核糖体的系统，但最近ARFA已被确定为在大肠杆菌中拯救核糖体的替代因子。这一过程需要RF2对新生的肽基-tRNA进行水解，RF2通常作为一种终止密码子特异性的肽释放因子。它提出了一个有趣的问题，即ARFA和RF2如何识别和拯救停滞不前的核糖体。在这里，我们通过定向羟基自由基探针定位了ARFA在停滞的核糖体中的位置。它揭示了在30S亚基的颈区附近有一个ARFA结合位点，其中ARFA的N-末端和C-末端分别靠近解码中心和mRNA进入通道。ARFA和RF2依次进入停滞在mRNA中间或3‘端的核糖体，而RF2只有当核糖体停滞在mRNA的3’端时才能诱导ARFA的构象发生变化。在这些结果的基础上，我们提出了ARFA作为识别RF2结合后的靶核糖体的传感器。
Although trans-translation mediated by tmRNA-SmpB has long been known as the sole system to relieve bacterial stalled ribosomes, ArfA has recently been identified as an alternative factor for ribosome rescue in Escherichia coli. This process requires hydrolysis of nascent peptidyl-tRNA by RF2, which usually acts as a stop codon-specific peptide release factor. It poses a fascinating question of how ArfA and RF2 recognize and rescue the stalled ribosome. Here, we mapped the location of ArfA in the stalled ribosome by directed hydroxyl radical probing. It revealed an ArfA-binding site around the neck region of the 30S subunit in which the N- and C-terminal regions of ArfA are close to the decoding center and the mRNA entry channel, respectively. ArfA and RF2 sequentially enter the ribosome stalled in either the middle or 3′ end of mRNA, whereas RF2 induces a productive conformational change of ArfA only when ribosome is stalled at the 3′ end of mRNA. On the basis of these results, we propose that ArfA functions as the sensor to recognize the target ribosome after RF2 binding.
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影响因子：
3.7
作者：
Ramadoss NS;Zhou X;Keiler KC
通讯作者：
Keiler KC
影响因子：
5.2
作者：
Abo T;Chadani Y
通讯作者：
Chadani Y
DOI：
10.1126/science.1217039
发表时间：
2012-03-16
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Neubauer C;Gillet R;Kelley AC;Ramakrishnan V
通讯作者：
Ramakrishnan V
DOI：
10.1261/rna.045773.114
发表时间：
2014-11
期刊：
RNA (New York, N.Y.)
影响因子：
--
作者：
Kurita D;Miller MR;Muto A;Buskirk AR;Himeno H
通讯作者：
Himeno H
影响因子：
5.2
作者：
Himeno H;Kurita D;Muto A
通讯作者：
Muto A