Sequence-specific recognition of colicin E5, a tRNA-targeting ribonuclease.
Sequence-specific recognition of colicin E5, a tRNA-targeting ribonuclease.
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DOI：
10.1093/nar/gkl629
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发表时间：
2006
影响因子：
14.9
通讯作者：
Masaki H
中科院分区：
文献类型：
--
作者：
Ogawa T;Inoue S;Yajima S;Hidaka M;Masaki H
大肠杆菌素E5是一种新的大肠杆菌核糖核酸酶，它能特异性地切割tRNATyr、tRNAHis、tRNAAsn和tRNAAsp的反密码子。由于这种活性仅限于其115个氨基酸长的C-末端结构域（CRD），因此E5-CRD的识别机制引起了极大的兴趣。四种tRNA底物在其反密码子环内共享独特序列UQU，并且在Q（G的修饰碱基）和3′ U之间被切割。与底物tRNA对应的合成微螺旋RNA对E5-CRD完全敏感，并以与真实tRNA相同的方式被切割。E5-CRD的特异性决定簇是YGUN，位于“反密码子”的−1至+3处。YGU是绝对必需的，其敏感性程度取决于反密码子的第三个字母N，顺序为A > C > G > U，说明敏感性顺序为tRNATyr > tRNAAsp > tRNAHis，tRNAAsn。相反，我们表明GpUp是严格保留对E5-CRD特异性的最小底物。连续核苷酸的作用在环状和线性RNA之间不一致，这表明GpUp两侧的核苷酸延伸引入了结构限制，该限制通过包括5′嘧啶和3′ A的特定环状结构形成而减少。
Colicin E5 is a novel Escherichia coli ribonuclease that specifically cleaves the anticodons of tRNATyr, tRNAHis, tRNAAsn and tRNAAsp. Since this activity is confined to its 115 amino acid long C-terminal domain (CRD), the recognition mechanism of E5-CRD is of great interest. The four tRNA substrates share the unique sequence UQU within their anticodon loops, and are cleaved between Q (modified base of G) and 3′ U. Synthetic minihelix RNAs corresponding to the substrate tRNAs were completely susceptible to E5-CRD and were cleaved in the same manner as the authentic tRNAs. The specificity determinant for E5-CRD was YGUN at −1 to +3 of the ‘anticodon’. The YGU is absolutely required and the extent of susceptibility of minihelices depends on N (third letter of the anticodon) in the order A > C > G > U accounting for the order of susceptibility tRNATyr > tRNAAsp > tRNAHis, tRNAAsn. Contrastingly, we showed that GpUp is the minimal substrate strictly retaining specificity to E5-CRD. The effect of contiguous nucleotides is inconsistent between the loop and linear RNAs, suggesting that nucleotide extension on each side of GpUp introduces a structural constraint, which is reduced by a specific loop structure formation that includes a 5′ pyrimidine and 3′ A.
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影响因子：
5.6
作者：
KAUFMANN, G;DAVID, M;SNYDER, L
通讯作者：
SNYDER, L
影响因子：
4.1
作者：
Pommer, AJ;Wallis, R;Kleanthous, C
通讯作者：
Kleanthous, C
影响因子：
2.9
作者：
Lin, YL;Elias, Y;Huang, RH
通讯作者：
Huang, RH
影响因子：
5.7
作者：
DOUDNA, JA
通讯作者：
DOUDNA, JA
影响因子：
3.9
作者：
Braun, V;Patzer, SI;Hantke, K
通讯作者：
Hantke, K