The contribution of the C5 protein subunit of Escherichia coli ribonuclease P to specificity for precursor tRNA is modulated by proximal 5' leader sequences.
The contribution of the C5 protein subunit of Escherichia coli ribonuclease P to specificity for precursor tRNA is modulated by proximal 5' leader sequences.
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DOI：
10.1261/rna.056408.116
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发表时间：
2017-10
期刊：
影响因子：
--
通讯作者：
Harris ME
中科院分区：
文献类型：
--
作者：
Niland CN;Anderson DR;Jankowsky E;Harris ME
RNA加工酶和RNA结合蛋白对RNA的识别通常涉及多个亚基之间的合作。然而，RNA和蛋白质亚基对核糖核蛋白分子识别的相互依赖的贡献相对未被探索。RNase P是一种核酸内切酶，能从前体tRNA中去除5′前导序列，在细菌中作为二聚体发挥作用，二聚体由催化RNA亚基（P RNA）和蛋白质亚基（E.大肠杆菌）。P RNA亚基接触tRNA体和近端5′前导序列[N（−1）和N（−2）]，而C5结合远端5′前导序列[N（−3）至N（−6）]。为了确定P RNA和C5形成的接触是否独立地贡献特异性或表现出协同性或反协同性，我们比较了6个近端5′前导核苷酸（n = 4096）的所有可能组合的相对kcat/Km值，以供E. coli P RNA亚基单独和通过RNase P全酶。我们观察到，虽然P RNA亚基对5′前导核苷酸N（−2）和N（−1）表现出特异性，但C5蛋白的存在降低了P RNA对特异性的贡献，但改变了N（−2）和N（−3）的特异性。结果表明，C5蛋白对RNase P加工的贡献是由前体tRNA 5′前导序列中N（−2）的身份控制的。数据还清楚地表明，tRNA的5′前导序列与3′ ACCA的配对作为RNase P切割的反决定簇。对基因组编码的E. colitRNAs的结果表明，这两个反决定簇在体内都受到负选择。
Recognition of RNA by RNA processing enzymes and RNA binding proteins often involves cooperation between multiple subunits. However, the interdependent contributions of RNA and protein subunits to molecular recognition by ribonucleoproteins are relatively unexplored. RNase P is an endonuclease that removes 5′ leaders from precursor tRNAs and functions in bacteria as a dimer formed by a catalytic RNA subunit (P RNA) and a protein subunit (C5 in E. coli). The P RNA subunit contacts the tRNA body and proximal 5′ leader sequences [N(−1) and N(−2)] while C5 binds distal 5′ leader sequences [N(−3) to N(−6)]. To determine whether the contacts formed by P RNA and C5 contribute independently to specificity or exhibit cooperativity or anti-cooperativity, we compared the relative kcat/Km values for all possible combinations of the six proximal 5′ leader nucleotides (n = 4096) for processing by the E. coli P RNA subunit alone and by the RNase P holoenzyme. We observed that while the P RNA subunit shows specificity for 5′ leader nucleotides N(−2) and N(−1), the presence of the C5 protein reduces the contribution of P RNA to specificity, but changes specificity at N(−2) and N(−3). The results reveal that the contribution of C5 protein to RNase P processing is controlled by the identity of N(−2) in the pre-tRNA 5′ leader. The data also clearly show that pairing of the 5′ leader with the 3′ ACCA of tRNA acts as an anti-determinant for RNase P cleavage. Comparative analysis of genomically encoded E. coli tRNAs reveals that both anti-determinants are subject to negative selection in vivo.
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影响因子：
2.9
作者：
Lin HC;Yandek LE;Gjermeni I;Harris ME
通讯作者：
Harris ME
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ALTMAN, S;GUERRIERTAKADA, C
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64.5
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GUERRIERTAKADA, C;MCCLAIN, WH;ALTMAN, S
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影响因子：
5.6
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