The bacterial histone-like protein HU specifically recognizes similar structures in all nucleic acids - DNA, RNA, and their hybrids
The bacterial histone-like protein HU specifically recognizes similar structures in all nucleic acids - DNA, RNA, and their hybrids
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DOI：
10.1074/jbc.m201978200
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发表时间：
2002-08-02
影响因子：
4.8
通讯作者：
Rouviere-Yaniv, J
中科院分区：
文献类型：
--
作者：
Balandina, A;Kamashev, D;Rouviere-Yaniv, J
HU是细菌类核的主要成分，与组蛋白、高迁移率族蛋白（HMG）和其他真核蛋白具有相同的性质。HU参与细菌细胞的许多主要途径，与双链体DNA无序列特异性结合，但以高亲和力识别DNA修复中间体。在这里，我们证明了HU以类似的低亲和力结合双链DNA、双链RNA和线性DNA-RNA双链体。与这种与总细胞RNA和超螺旋DNA的非特异性结合相反，HU特异性识别DNA和RNA共同的特定结构。特别地，HU特异性结合有切口或有缺口的DNA-RNA杂交体和复合RNA分子，例如DsrA，一种小的非编码RNA。HU调节DNA结构，可能通过其RNA结合能力在细菌机制中发挥额外的关键功能。它的结合结构域具有两个高度灵活的β-带状臂和一个α-螺旋平台的简单、直接的结构，是显示双重DNA和RNA特异性结合能力的真核蛋白质的精细结合结构域的替代模型。
HU, a major component of the bacterial nucleoid, shares properties with histones, high mobility group proteins (HMGs), and other eukaryotic proteins. HU, which participates in many major pathways of the bacterial cell, binds without sequence specificity to duplex DNA but recognizes with high affinity DNA repair intermediates. Here we demonstrate that HU binds to double-stranded DNA, double-stranded RNA, and linear DNA-RNA duplexes with a similar low affinity. In contrast to this nonspecific binding to total cellular RNA and to supercoiled DNA, HU specifically recognizes defined structures common to both DNA and RNA. In particular HU binds specifically to nicked or gapped DNA-RNA hybrids and to composite RNA molecules such as DsrA, a small non-coding RNA. HU, which modulates DNA architecture, may play additional key functions in the bacterial machinery via its RNA binding capacity. The simple, straightforward structure of its binding domain with two highly flexible beta-ribbon arms and an alpha-helical platform is an alternative model for the elaborate binding domains of the eukaryotic proteins that display dual DNA- and RNA-specific binding capacities.