Julian N, Demene H, Morellet N, Maigret B, Roques B P
Département de Pharmacochimie Moléculaire et Structurale, U266 INSERM-URA D1500 CNRS, Faculté de Pharmacie, Paris, France.
FEBS Lett. 1993 Sep 27;331(1-2):43-8. doi: 10.1016/0014-5793(93)80294-5.
The nucleocapsid protein NCp7 of human immunodeficiency virus type 1 (HIV-1), which is necessary for the formation of infectious virions, contains two zinc fingers of the Cys-X2-Cys-X4-His-X4-Cys form. To elucidate the importance of this particular motif, well conserved in retroviruses and retroelements, we substituted the histidine residue by a cysteine in the first zinc binding domain 13VKCFNCGKEGHTARNCRA30. The structures of the mutated and native zinc complexed peptides were studied by two-dimensional 600 MHz 1H nuclear magnetic resonance (NMR) in aqueous solution. The nuclear Overhauser effects were used as constraints to determine the solution structures using DIANA software followed by AMBER energy refinement. The results show that native and mutant peptides fold into non-identical three-dimensional structures, probably accounting for the loss of retrovirus infectivity following the His-Cys point mutation.
人类免疫缺陷病毒1型（HIV-1）的核衣壳蛋白NCp7是形成感染性病毒粒子所必需的，它含有两个Cys-X2-Cys-X4-His-X4-Cys形式的锌指结构。为了阐明这种在逆转录病毒和逆转录元件中高度保守的特定基序的重要性，我们将第一个锌结合结构域13VKCFNCGKEGHTARNCRA30中的组氨酸残基替换为半胱氨酸。通过二维600 MHz 1H核磁共振（NMR）在水溶液中研究了突变型和天然锌络合肽的结构。利用核Overhauser效应作为约束条件，使用DIANA软件确定溶液结构，随后进行AMBER能量优化。结果表明，天然肽和突变肽折叠成不同的三维结构，这可能是组氨酸-半胱氨酸点突变后逆转录病毒感染性丧失的原因。
