Comparison of the intermolecular interfaces and chemical crosslinking patterns between CA and CA-SP1-NC structures.

<p>(A) Superposition of the CA monomer model from the assembled CA structure (gold) and that from the assembled CA-SP1-NC structure (blue). (B–D) Superposition of the CA-NTD models at the NTD interfaces (B&C) and CA-CTD models at the trimer interface (D). The color scheme is identical to (A). Space-filling representation highlights the specific residue pairs; 17/19 in (B), 14/45 in (C) and 207/216 in (D), with red corresponding to those from CA and cyan to those from CA-SP1-NC. (E) Non-reducing SDS-PAGE analysis of <i>in vitro</i> disulfide crosslinked CA (lanes 2, 4 and 6) and CA-SP1-NC assemblies (lanes 3, 5 and 7), stained with Coomassie Blue. Lanes were rearranged from original gels shown in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002886#ppat.1002886.s003" target="_blank">Fig. S3</a>. (F) Non-reducing SDS-PAGE analysis of crosslinking of mature (lanes 2, 4 and 7) and cleavage-defective HIV-1 CA6 particles (lanes 3, 5 and 6). Proteins were detected by immunoblotting with a CA-specific antibody.