@article{TEXTUAL,
      recid = {9673},
      author = {Tan, Aaron and Pak, Alexander J. and Morado, Dustin R. and  Voth, Gregory A. and Briggs, John A. G.},
      title = {Immature HIV-1 assembles from Gag dimers leaving partial  hexamers at lattice edges as potential substrates for  proteolytic maturation},
      journal = {PNAS},
      address = {2021-01-04},
      number = {TEXTUAL},
      abstract = {The CA (capsid) domain of immature HIV-1 Gag and the  adjacent spacer peptide 1 (SP1) play a key role in viral  assembly by forming a lattice of CA hexamers, which adapts  to viral envelope curvature by incorporating small lattice  defects and a large gap at the site of budding. This  lattice is stabilized by intrahexameric and interhexameric  CA-CA interactions, which are important in regulating viral  assembly and maturation. We applied subtomogram averaging  and classification to determine the oligomerization state  of CA at lattice edges and found that CA forms partial  hexamers. These structures reveal the network of  interactions formed by CA-SP1 at the lattice edge. We also  performed atomistic molecular dynamics simulations of CA-CA  interactions stabilizing the immature lattice and partial  CA-SP1 helical bundles. Free energy calculations reveal  increased propensity for helix-to-coil transitions in  partial hexamers compared to complete six-helix bundles.  Taken together, these results suggest that the CA dimer is  the basic unit of lattice assembly, partial hexamers exist  at lattice edges, these are in a helix-coil dynamic  equilibrium, and partial helical bundles are more likely to  unfold, representing potential sites for HIV-1 maturation  initiation.},
      url = {http://knowledge.uchicago.edu/record/9673},
}