Zhai Yujia, Sun Fei, Li Xuemei, Pang Hai, Xu Xiaoling, Bartlam Mark, Rao Zihe
Tsinghua-lnstitute of Biophysics Joint Research Group for Structural Biology, Tsinghua University, Beijing 100084, China.
Nat Struct Mol Biol. 2005 Nov;12(11):980-6. doi: 10.1038/nsmb999.
Coronavirus replication and transcription machinery involves multiple virus-encoded nonstructural proteins (nsp). We report the crystal structure of the hexadecameric nsp7-nsp8 supercomplex from the severe acute respiratory syndrome coronavirus at 2.4-angstroms resolution. nsp8 has a novel 'golf-club' fold with two conformations. The supercomplex is a unique hollow, cylinder-like structure assembled from eight copies of nsp8 and held tightly together by eight copies of nsp7. With an internal diameter of approximately 30 angstroms, the central channel has dimensions and positive electrostatic properties favorable for nucleic acid binding, implying that its role is to confer processivity on RNA-dependent RNA polymerase.
冠状病毒的复制和转录机制涉及多种病毒编码的非结构蛋白（nsp）。我们报道了严重急性呼吸综合征冠状病毒十六聚体nsp7-nsp8超复合物的晶体结构，分辨率为2.4埃。nsp8具有一种新型的“高尔夫球杆”折叠结构，有两种构象。该超复合物是一种独特的中空圆柱状结构，由八个nsp8拷贝组装而成，并由八个nsp7拷贝紧密结合在一起。中央通道的内径约为30埃，其尺寸和正静电性质有利于核酸结合，这意味着它的作用是赋予依赖RNA的RNA聚合酶持续性。
