Broad Distribution of Energetically Important Contacts across an Extended Protein Interface.
Johnson, L.M., Horne, W.S., Gellman, S.H.(2011) J Am Chem Soc 133: 10038-10041
- PubMed: 21644542 
- DOI: https://doi.org/10.1021/ja203358t
- Primary Citation of Related Structures:  
3O3X, 3O3Z, 3O40, 3O43 - PubMed Abstract: 
Infection of cells by HIV depends upon profound structural rearrangements within the trimeric viral protein gp41. Critical to this process is the formation of a six-helix bundle in which a set of three N-terminal heptad repeat (NHR) helices assemble to form a core displaying long grooves that provide docking sites for three C-terminal heptad repeat (CHR) helices. We report experiments designed to discriminate between two alternative hypotheses regarding the source of affinity between individual CHR helices and the complementary groove: (1) affinity is dominated by interactions of a small cluster of side chains at one end of the CHR helix; or (2) affinity depends upon interactions distributed across the long CHR helix. We have employed two complementary experimental designs, and results from both favor the latter hypothesis.
Organizational Affiliation: 
Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.