Large Favorable Enthalpy Changes Drive Specific RNA Recognition by RNA Recognition Motif Proteins
Large Favorable Enthalpy Changes Drive Specific RNA Recognition by RNA Recognition Motif Proteins
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DOI：
10.1021/bi102057m
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发表时间：
2011-03-08
期刊：
影响因子：
2.9
通讯作者：
Kielkopf, Clara L.
中科院分区：
文献类型：
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作者：
McLaughlin, Krystle J.;Jenkins, Jermaine L.;Kielkopf, Clara L.
RNA识别基序(RRM)是一类普遍存在的RNA结合域。虽然已经确定了一些RRM/RNA结构，但热力学分析相对较少。在这里，我们使用等温滴定热量计来表征四种具有代表性的含有RRM的蛋白质与单链(Ss)RNA的结合：(I)U2AF(65)，(Ii)SXL，(Iii)TIA-1，和(Iv)PAB。在所有情况下，单链RNA结合都伴随着非常大的有利热变(-30至-60千卡摩尔(-1))和不利的熵变。关键的RRM残基和结合位点的变化表明，在这些研究的几乎生理条件下，巨大的热力学变化代表着RRMS识别特定的单链RNA的特征。
The RNA recognition motif (RRM) is a prevalent class of RNA binding domains. Although a number of RRM/RNA structures have been determined, thermodynamic analyses are relatively uncommon. Here, we use isothermal titration calorimetry to characterize single-stranded (ss)RNA binding by four representative RRM-containing proteins: (i) U2AF(65), (ii) SXL, (iii) TIA-1, and (iv) PAB. In all cases, ssRNA binding is accompanied by remarkably large favorable enthalpy changes (-30 to -60 kcal mol(-1)) and unfavorable entropy changes. Alterations of key RRM residues and binding sites indicate that under the nearly physiological conditions of these studies, large thermodynamic changes represent a signature of specific ssRNA recognition by RRMs.