Biology Reference
In-Depth Information
Fig. 9.
Structures of HIV-1 NC protein-RNA complexes. Shown are the
SL2 RNA-NC complex (A and B) and the SL3 RNA-NC complex (C and D).
A and C show overviews of the two structures, B and D show the interactions
of a crucial guanine nucleotide in both structures (1F6U, 1AIT).
genomic RNA exists inside the virion as a dimmer, and the overlap of
the RNA sequences that control dimerization and packaging indi-
cates that these processes are coupled.
76-78
This interlay of RNA-RNA
and RNA-protein interactions was recently demonstrated for the
Ψ
-site RNA of MMLV, where a dimerization-induced register shift in
base-pairing exposes conserved UCUG elements that bind the NC
protein with very high affinity.
79
These elements are base-paired in
the monomeric RNA and do not bind NC protein. This represents
