Generation of MLV Gag^Core L-domain chimeras.

<p>(A) HBV Core encodes a putative L-domain motif suggesting a potential docking site for HECT Ub ligases that direct HBV release. (B) L-domain chimeric proteins between MLV Gag and Core were generated by replacement of the endogenous MLV PPPY motif with the Core PPAY/PNAP motif and flanking residues. The location of the MLV Gag PPPY motif in the p12 region is italicized. The Gag4A mutant contains four alanine amino acid substitutions (AAAA) that abolish Gag L-domain activity. The inserted Core sequence is underlined in the MLV L-domain chimeras. The L-domain motif and L-domain motif mutations are italicized. Chimeric Gag protein was subcloned into the MLV GagPol expression plasmid to generate GagPol, GagPol4A, GagPol^PPAY/PNAP, GagPol^PPAY, GagPol^PNAP, GagPol^LPAY/PNAP, GagPol^PPAF/PNAP, and GagPol^PPAA/PNAP expression constructs. The MLV Pr65 Gag protein contains matrix (MA), capsids (CA), and nucleocapsid (NC) domains. Asterisks indicate PR cleavage sites.