Morellet N, Jullian N, De Rocquigny H, Maigret B, Darlix J L, Roques B P
Département de Chimie Organique, U 266 INSERM, UA 498 CNRS, UFR des Sciences Pharmaceutiques et Biologiques, Paris, France.
EMBO J. 1992 Aug;11(8):3059-65. doi: 10.1002/j.1460-2075.1992.tb05377.x.
The retroviral gag nucleocapsid protein NCp7 (72 amino acids) of HIV-1 (LAV strain), which contains two successive zinc fingers of the Cys-X2-Cys-X4-His-X4-Cys form linked by a stretch of basic residues, promotes viral RNA dimerization and encapsidation and activates annealing of the primer tRNA to the initiation site of reverse transcription. The structure of NCp7 and other shorter fragments was studied by 600 MHz 1H nuclear magnetic resonance (NMR) in aqueous solution to account for its various biological properties. Complete sequence specific 1H NMR assignments of the 13-51 residues of NCp7 encompassing the two zinc fingers was achieved by two-dimensional NMR experiments and the three-dimensional structure of (13-51)NCp7 was deduced from DIANA calculations, using nuclear Overhauser effects as constraints. The structure of the zinc complexed form of NCp7 is characterized by a kink at the Pro31 level in the basic Arg29-Ala-Pro-Arg-Lys-Lys-Gly35 RNA binding linker leading to a proximity of the Lys14-Cys18 to the Gly35-Cys39 sequences, which belong to the folded proximal and distal zinc fingers, respectively. Accordingly, the aromatic residues Phe16 and Trp37 were found to be spatially close. The Lys33 and Lys34 side-chains involved in viral RNA dimerization were solvent exposed. The N- and C-terminal sequences of NCp7 behave as flexible independent domains. The proposed structure of NCp7 might be used to rationally design new anti-viral agents aimed at inhibiting its functions.
人类免疫缺陷病毒1型（LAV株）的逆转录病毒群核衣壳蛋白NCp7（72个氨基酸）含有两个连续的Cys-X2-Cys-X4-His-X4-Cys形式的锌指，由一段碱性残基相连，可促进病毒RNA二聚化和衣壳化，并激活引物tRNA与逆转录起始位点的退火。通过600 MHz 1H核磁共振（NMR）在水溶液中研究了NCp7和其他较短片段的结构，以解释其各种生物学特性。通过二维NMR实验实现了对包含两个锌指的NCp7的13-51位残基的完整序列特异性1H NMR归属，并以核Overhauser效应为约束条件，从DIANA计算中推导了（13-51）NCp7的三维结构。NCp7锌络合形式的结构特征是在碱性Arg29-Ala-Pro-Arg-Lys-Lys-Gly35 RNA结合连接子的Pro31水平处有一个扭结，导致Lys14-Cys18与Gly35-Cys39序列接近，这两个序列分别属于折叠的近端和远端锌指。因此，发现芳香族残基Phe16和Trp37在空间上接近。参与病毒RNA二聚化的Lys33和Lys34侧链暴露于溶剂中。NCp7的N端和C端序列表现为灵活的独立结构域。所提出的NCp7结构可用于合理设计旨在抑制其功能的新型抗病毒药物。
