Mujeeb A, Clever J L, Billeci T M, James T L, Parslow T G
Department of Pathology, University of California at San Francisco, 94143, USA.
Nat Struct Biol. 1998 Jun;5(6):432-6. doi: 10.1038/nsb0698-432.
Retroviral genomes must dimerize to be fully infectious. Dimerization is directed by a unique RNA hairpin structure with a palindrome in its loop: hairpins of two strands first associate transiently through their loops, and then refold to a more stable, linear duplex. The structure of the initial, kissing-loop dimer from HIV-1, solved using 2D NMR, is bent and metastable, its interface being formed not only by standard basepairing between palindromes, but also by a distinctive pattern of interstrand stacking among bases at the stem-loop junctions. This creates mechanical distortions that partially melt both stems, which may facilitate spontaneous refolding of this RNA complex into linear form.
逆转录病毒基因组必须二聚化才能具有完全传染性。二聚化由一种独特的RNA发夹结构引导，其环中含有回文序列：两条链的发夹首先通过它们的环短暂结合，然后重新折叠成更稳定的线性双链体。利用二维核磁共振解析得到的HIV-1初始吻环二聚体结构是弯曲且亚稳定的，其界面不仅由回文序列之间的标准碱基配对形成，还由茎环连接处碱基之间独特的链间堆积模式形成。这会产生机械扭曲，使两个茎部分解链，这可能有助于这种RNA复合物自发重折叠成线性形式。
