NMR structure of the mature dimer initiation complex of HIV‐1 genomic RNA

FEBS Letters

James, Thomas L.²  Das, Chandreyee²  Zarrinpar, Ali¹  Parslow, Tristram G.³  Mujeeb, Anwer² 

[1]Department of Biochemistry, University of California at San Francisco, San Francisco, CA 94143, USA

[2]Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA 94143, USA

[3]Department of Pathology, Box 0506, University of California at San Francisco, San Francisco, CA 94143, USA

关键词: Dimerization;    HIV-1 genome;    NMR;    RNA-RNA interaction;    RNA structure;    Packaging;   

DOI  :  10.1016/S0014-5793(99)01183-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The two identical genomic RNA strands inside each HIV-1 viral particle are linked through homodimerization of an RNA stem-loop, termed SL1, near their 5′ ends. SL1 first dimerizes through a palindromic sequence in its loop, forming a transient kissing-loop complex which then refolds to a mature, linear duplex. We previously reported the NMR structure of a 23-base truncate of SL1 in kissing-dimer form, and here report the high-resolution structure of its linear isoform. This structure comprises three short duplex regions – derived from the central palindrome and two stem regions of each strand, respectively – separated by two bulges that each encompass three unpaired adenines flanking the palindromes. The stacking pattern of these adenines differs from that seen in the kissing-loop complex, and leads to greater colinear base stacking overall. Moreover, the mechanical distortion of the palindrome helix is reduced, and base pairs ruptured during formation of the kissing-loop complex are re-established, so that all potential Watson-Crick pairs are intact. These features together likely account for the greater thermodynamic stability of the mature dimer as compared to its kissing-loop precursor.

【 授权许可】

Unknown