Structures of the HIV-1 capsid protein dimerization domain at 2.6 A resolution.
Structures of the HIV-1 capsid protein dimerization domain at 2.6 A resolution.
复制标题
HIV-1 衣壳蛋白二聚结构域的结构，分辨率为 2.6 A。
DOI：
10.1107/s0907444998007689
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Hill,CP
中科院分区：
文献类型：
--
作者：
Worthylake,DK;Wang,H;Yoo,S;Sundquist,WI;Hill,CP
人类免疫缺陷病毒I型（HIV-1）衣壳蛋白最初合成为Gag多蛋白的中心结构域，随后经蛋白水解加工成离散的231个氨基酸的蛋白质，形成成熟病毒的独特锥形核心。本文报道了跨越衣壳C-末端结构域的两种蛋白质的晶体结构：一种包含残基146-231（CA 146 -231），另一种延伸至包括Gag的14-残基p2结构域（CA 146-p2）。通过分子置换确定了同晶CA 146 -231和CA 146-p2结构，并在2.6 Å分辨率下分别细化至R因子22.3和20.7%（Rfree = 28.1和27.5%）。 有序结构域包含CA 146 -231的残基148-219和CA 146-p2的残基148-218，并且它们的精制结构基本上相同。这些蛋白质由一个310螺旋，随后是一个延伸链和四个α螺旋组成。晶体学双折叠产生二聚体，其通过α-螺旋2穿过二聚体界面的平行包装以及通过将310螺旋包装到由伴侣分子的α-螺旋2和3产生的凹槽中而稳定。CA 146 -231和CA 146-p2以完整衣壳蛋白的完全亲和力二聚化，因此它们的结构揭示了HIV-1衣壳的基本二聚体界面。
The human immunodeficiency virus type I (HIV-1) capsid protein is initially synthesized as the central domain of the Gag polyprotein, and is subsequently proteolytically processed into a discrete 231-amino-acid protein that forms the distinctive conical core of the mature virus. The crystal structures of two proteins that span the C-terminal domain of the capsid are reported here: one encompassing residues 146–231 (CA146–231) and the other extending to include the 14-residue p2 domain of Gag (CA146–p2). The isomorphous CA146–231 and CA146–p2 structures were determined by molecular replacement and have been refined at 2.6 Å resolution to R factors of 22.3 and 20.7% (Rfree = 28.1 and 27.5%), respectively. The ordered domains comprise residues 148–219 for CA146–231 and 148–218 for CA146–p2, and their refined structures are essentially identical. The proteins are composed of a 310 helix followed by an extended strand and four α-helices. A crystallographic twofold generates a dimer that is stabilized by parallel packing of an α-helix 2 across the dimer interface and by packing of the 310 helix into a groove created by α-helices 2 and 3 of the partner molecule. CA146–231 and CA146–p2 dimerize with the full affinity of the intact capsid protein, and their structures therefore reveal the essential dimer interface of the HIV-1 capsid.