The CRM domain: An RNA binding module derived from an ancient ribosome-associated protein
The CRM domain: An RNA binding module derived from an ancient ribosome-associated protein
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DOI：
10.1261/rna.139607
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发表时间：
2007-01-01
期刊：
影响因子：
4.5
通讯作者：
Watkins, Kenneth P.
中科院分区：
文献类型：
--
作者：
Barkan, Alice;Klipcan, Larik;Watkins, Kenneth P.
CRS 1-YhbY结构域（也称为CRM结构域）在细菌和细菌中以独立蛋白质的形式存在，在植物中以单结构域和多结构域蛋白质家族的形式存在。该结构域的功能尚不清楚，但结构数据和已知与RNA相互作用的几种蛋白质中存在的结构域导致了它结合RNA的建议。在这里，我们描述了一个系统发育分析的域，其纳入不同的蛋白质在植物中，和生化特性的原核和真核的域家族的代表。我们发现，该家族的细菌成员，大肠杆菌YhbY，与前50 S核糖体亚基，这表明YhbY功能在核糖体组装。GFP融合到来自玉米的单结构域CRM蛋白定位于核仁，这表明类似的活性可能已经保留在植物中。我们进一步表明，一个分离的玉米CRM结构域在体外具有RNA结合活性，并且与KH RNA结合结构域共享的一个小基序，一个保守的“GxxG”环，有助于其RNA结合活性。这些和其他结果表明，CRM结构域进化的背景下，核糖体功能的分歧之前，细菌和细菌，这种功能一直保持在现存的原核生物，该域被招募，作为一个RNA结合模块在植物基因组的进化。
The CRS1-YhbY domain (also called the CRM domain) is represented as a stand-alone protein in Archaea and Bacteria, and in a family of single- and multidomain proteins in plants. The function of this domain is unknown, but structural data and the presence of the domain in several proteins known to interact with RNA have led to the proposal that it binds RNA. Here we describe a phylogenetic analysis of the domain, its incorporation into diverse proteins in plants, and biochemical properties of a prokaryotic and eukaryotic representative of the domain family. We show that a bacterial member of the family, Escherichia coli YhbY, is associated with pre-50S ribosomal subunits, suggesting that YhbY functions in ribosome assembly. GFP fused to a single- domain CRM protein from maize localizes to the nucleolus, suggesting that an analogous activity may have been retained in plants. We show further that an isolated maize CRM domain has RNA binding activity in vitro, and that a small motif shared with KH RNA binding domains, a conserved "GxxG'' loop, contributes to its RNA binding activity. These and other results suggest that the CRM domain evolved in the context of ribosome function prior to the divergence of Archaea and Bacteria, that this function has been maintained in extant prokaryotes, and that the domain was recruited to serve as an RNA binding module during the evolution of plant genomes.