Preferential binding of fd gene 5 protein to tetraplex nucleic acid structures
Preferential binding of fd gene 5 protein to tetraplex nucleic acid structures
复制标题
DOI：
10.1006/jmbi.2000.3991
复制
发表时间：
2000-08-18
影响因子：
5.6
通讯作者：
Kneale, GG
中科院分区：
文献类型：
--
作者：
Oliver, AW;Bogdarina, I;Kneale, GG
丝状噬菌体fd的基因5蛋白是单链DNA结合蛋白，其非特异性结合所有单链核酸序列，但另外能够特异性结合序列d（GT（5）G（4）CT（4）C）和RNA等价物r（GU（5）G（4）CU（4）C），后者的相互作用对于翻译抑制是重要的。我们发现，这种序列偏好产生于形成一个四链体结构举行在一起的一个中心块的G-四联体，其结构持续在复杂的基因5蛋白。基因5蛋白与四链体的结合导致形成类似于170 kDa的核蛋白复合物，其由四条寡核苷酸链和八个基因5蛋白二聚体组成，回转半径为45埃，总体最大尺寸为120-130埃。复杂的模型是一致的，与所获得的数据。有人提出，G-四联体可能作为一个成核位点结合基因5蛋白质的相邻单链区域，这表明一种新的翻译抑制机制。(C)北京大学出版社.
The gene 5 protein of filamentous bacteriophage fd is a single-stranded DNA-binding protein that binds non-specifically to all single-stranded nucleic acid sequences, but in addition is capable of specific binding to the sequence d(GT(5)G(4)CT(4)C) and the RNA equivalent r(GU(5)G(4)CU(4)C), the latter interaction being important for translational repression. We show that this sequence preference arises from the formation of a tetraplex structure held together by a central block of G-quartets, the structure of which persists in the complex with gene 5 protein. Binding of gene 5 protein to the tetraplex leads to formation of a similar to 170 kDa nucleoprotein complex consisting of four oligonucleotide strands and eight gene 5 protein dimers, with a radius of gyration of 45 Angstrom and an overall maximum dimension of 120-130 Angstrom. A model of the complex is presented that is consistent with the data obtained. It is proposed that the G-quartet may act as a nucleation site for binding gene 5 protein to adjacent single-stranded regions, suggesting a novel mechanism for translational repression. (C) 2000 Academic Press.