Characterization of RNA sequence determinants and antideterminants of processing reactivity for a minimal substrate of Escherichia coli ribonuclease III.
Characterization of RNA sequence determinants and antideterminants of processing reactivity for a minimal substrate of Escherichia coli ribonuclease III.
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RNA序列决定因素和氧化反应性的表征对大肠杆菌核糖核酸酶的最小底物的加工反应性。
DOI：
10.1093/nar/gkl459
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发表时间：
2006
影响因子：
14.9
通讯作者：
Nicholson, Allen W.
中科院分区：
文献类型：
--
作者：
Pertzev, Alexandre V.;Nicholson, Allen W.
核糖核酸酶III家族的成员是原核生物和真核细胞中双链（DS）RNA加工的主要药物。速率。盒子（DB）和近端盒（PB）表征了E.Coli RNase III的最小底物，并用来定义DB和PB序列的要求及其参与裂解位点在裂解和体外结合中检查了μR1.1RNA序列变异。 RNase III的阳性确定剂，具有最佳识别的典型UA/UG序列会议。在PB中抑制RNase III结合的位置是由于嘌呤2-氨基氨基群体，该基团可作为较小的凹槽识别抗体剂。在相邻的PB位置，与剪刀键相邻的位置可以抑制裂解而无需抑制结合，从而充当催化反替代剂。两个盒子作为阳性识别决定了反应性的基本对序列控制，在细菌RNase III的催化后复合物的新结构信息中进行了讨论基材。
Members of the ribonuclease III family are the primary agents of double-stranded (ds) RNA processing in prokaryotic and eukaryotic cells. Bacterial RNase III orthologs cleave their substrates in a highly site-specific manner, which is necessary for optimal RNA function or proper decay rates. The processing reactivities of Escherichia coli RNase III substrates are determined in part by the sequence content of two discrete double-helical elements, termed the distal box (db) and proximal box (pb). A minimal substrate of E.coli RNase III, μR1.1 RNA, was characterized and used to define the db and pb sequence requirements for reactivity and their involvement in cleavage site selection. The reactivities of μR1.1 RNA sequence variants were examined in assays of cleavage and binding in vitro. The ability of all examined substitutions in the db to inhibit cleavage by weakening RNase III binding indicates that the db is a positive determinant of RNase III recognition, with the canonical UA/UG sequence conferring optimal recognition. A similar analysis showed that the pb also functions as a positive recognition determinant. It also was shown that the ability of the GC or CG bp substitution at a specific position in the pb to inhibit RNase III binding is due to the purine 2-amino group, which acts as a minor groove recognition antideterminant. In contrast, a GC or CG bp at the pb position adjacent to the scissile bond can suppress cleavage without inhibiting binding, and thus act as a catalytic antideterminant. It is shown that a single pb+db ‘set’ is sufficient to specify a cleavage site, supporting the primary function of the two boxes as positive recognition determinants. The base pair sequence control of reactivity is discussed within the context of new structural information on a post-catalytic complex of a bacterial RNase III bound to the cleaved minimal substrate.
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影响因子：
64.5
作者：
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通讯作者：
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影响因子：
5.6
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作者：
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