Structural and functional studies of the phage Sf6 terminase small subunit reveal a DNA-spooling device facilitated by structural plasticity.
Structural and functional studies of the phage Sf6 terminase small subunit reveal a DNA-spooling device facilitated by structural plasticity.
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噬菌体SF6末端酶小亚基的结构和功能研究揭示了由结构可塑性促进的DNA挡管装置。
DOI：
10.1016/j.jmb.2012.07.016
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发表时间：
2012-10-26
影响因子：
5.6
通讯作者：
Tang, Liang
中科院分区：
文献类型：
--
作者：
Zhao, Haiyan;Kamau, Yvonne N.;Christensen, Theodore E.;Tang, Liang
在许多DNA病毒中，基因组包装由包装末端酶的小亚基启动，其特异性结合病毒DNA上的包装信号并指导末端酶全酶的组装。我们已经通过实验绘制了志贺病毒Sf6末端酶小亚基gp 1上的DNA相互作用区域，该区域占据了环绕gp 1八聚体的扩展表面积，表明DNA通过广泛的接触缠绕在gp 1周围。高分辨率的结构揭示了大规模的运动的gp 1 DNA结合域介导的由残基54-81和残基Arg 67和Glu 73形成的分子间盐桥形成的弯曲螺旋，表明显着的结构可塑性多价，多形性gp 1：DNA相互作用。这些结果提供了蛋白质：DNA相互作用的空间限制，这使得构建一个三维的伪原子模型的DNA包装起始复合物组装从末端酶小亚基和包装区域的病毒DNA。我们的研究结果表明，gp 1的功能作为一个DNA的spooling设备，这可能会将DNA转化为一个特定的架构，适合于相互作用和切割的末端酶大亚基之前，DNA易位到病毒前衣壳。这可能代表了加尾dsDNA细菌病毒中DNA包装起始步骤的共同机制。
In many DNA viruses, genome packaging is initiated by the small subunit of the packaging terminase, which specifically binds to the packaging signal on viral DNA and directs assembly of the terminase holoenzyme. We have experimentally mapped the DNA-interacting region on Shigella virus Sf6 terminase small subunit gp1, which occupies extended surface areas encircling the gp1 octamer, indicating that DNA wraps around gp1 through extensive contacts. High resolution structures reveal large-scale motions of the gp1 DNA-binding domain mediated by the curved helix formed by residues 54-81 and an intermolecular salt bridge formed by residues Arg67 and Glu73, indicating remarkable structural plasticity underlying multivalent, pleomorphic gp1:DNA interactions. These results provide spatial restraints for protein:DNA interactions, which enable construction of a three-dimensional pseudo-atomic model for a DNA-packaging initiation complex assembled from the terminase small subunit and the packaging region on viral DNA. Our results suggest that gp1 functions as a DNA-spooling device, which may transform DNA into a specific architecture appropriate for interaction with and cleavage by the terminase large subunit prior to DNA translocation into viral procapsid. This may represent a common mechanism for the initiation step of DNA packaging in tailed dsDNA bacterial viruses.
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影响因子：
5.6
作者：
Casjens, S;Winn-Stapley, DA;Clark, AJ
通讯作者：
Clark, AJ
噬菌体P22末端酶小亚基的组装结构和DNA结合。
影响因子：
5.6
作者：
Nemecek, Daniel;Lander, Gabriel C.;Johnson, John E.;Casjens, Sherwood R.;Thomas, George J., Jr.
通讯作者：
Thomas, George J., Jr.
DOI：
10.1107/s0907444902016657
发表时间：
2002-11-01
影响因子：
2.2
作者：
Adams, PD;Grosse-Kunstleve, RW;Terwilliger, TC
通讯作者：
Terwilliger, TC
影响因子：
11.4
作者：
King, JA;Dubielzig, R;Kleinschmidt, JA
通讯作者：
Kleinschmidt, JA
影响因子：
4
作者：
Ostapchuk, P;Hearing, P
通讯作者：
Hearing, P