NMR structure of the 101-nucleotide core encapsidation signal of the Moloney Murine Leukemia Virus.
D'Souza, V., Dey, A., Habib, D., Summers, M.F.(2004) J Mol Biol 337: 427-442
- PubMed: 15003457
- DOI: https://doi.org/10.1016/j.jmb.2004.01.037
- Primary Citation of Related Structures:
1S9S - PubMed Abstract:
The full length, positive-strand genome of the Moloney Murine Leukemia Virus contains a "core encapsidation signal" that is essential for efficient genome packaging during virus assembly. We have determined the structure of a 101-nucleotide RNA that contains this signal (called mPsi) using a novel isotope-edited NMR approach. The method is robust and should be generally applicable to larger RNAs. mPsi folds into three stem loops, two of which (SL-C and SL-D) co-stack to form an extended helix. The third stem loop (SL-B) is connected to SL-C by a flexible, four-nucleotide linker. The structure contains five mismatched base-pairs, an unusual C.CG base-triple platform, and a novel "A-minor K-turn," in which unpaired adenosine bases A340 and A341 of a GGAA bulge pack in the minor groove of a proximal stem, and a bulged distal uridine (U319) forms a hydrogen bond with the phosphodiester of A341. Phylogenetic analyses indicate that these essential structural elements are conserved among the murine C-type retroviruses.
Organizational Affiliation:
Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.