Single-molecule spectroscopic study of dynamic nanoscale DNA bending behavior of HIV-1 nucleocapsid protein.

We have studied the conformational dynamics associated with the nanoscale DNA bending induced by human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) protein using single-molecule Förster resonance energy transfer (SM-FRET). To gain molecular-level insights into how the HIV-1 NC locally distorts the structures of duplexed DNA segments, the dynamics, reversibility, and sequence specificity of the DNA bending behavior of NC have been systematically studied. We have performed SM-FRET measurements on a series of duplexed DNA segments with varying sequences, lengths, and local structures in the presence of the wide-type HIV-1 NC and NC mutants lacking either the basic N-terminal domain or the zinc fingers.

Binding of rabies virus polymerase cofactor to recombinant circular nucleoprotein-RNA complexes.

In rabies virus, the attachment of the L polymerase (L) to the viral nucleocapsids (NCs)-a nucleoprotein (N)-RNA complex that serves as template for RNA transcription and replication-is mediated by the polymerase cofactor, the phosphoprotein (P). P forms dimers (P(2)) that bind through their C-terminal domains (P(CTD)) to the C-terminal region of the N. Recombinant circular N(m)-RNA complexes containing 9 to 12 protomers of N (hereafter, the subscript m denotes the number of N protomers) served here as model systems for studying the binding of P to NC-like N(m)-RNA complexes.