Alvarez, Frances J. D.He, ShaodaPerilla, Juan R.Jang, SooinSchulten, KlausEngelman, AlanScheres, Sjors H. W.Zhang, Peijun2017-12-052017Alvarez, Frances J. D., Shaoda He, Juan R. Perilla, Sooin Jang, Klaus Schulten, Alan N. Engelman, Sjors H. W. Scheres, and Peijun Zhang. 2017. “CryoEM structure of MxB reveals a novel oligomerization interface critical for HIV restriction.” Science Advances 3 (9): e1701264. doi:10.1126/sciadv.1701264. http://dx.doi.org/10.1126/sciadv.1701264.http://nrs.harvard.edu/urn-3:HUL.InstRepos:34492005Human dynamin–like, interferon-induced myxovirus resistance 2 (Mx2 or MxB) is a potent HIV-1 inhibitor. Antiviral activity requires both the amino-terminal region of MxB and protein oligomerization, each of which has eluded structural determination due to difficulties in protein preparation. We report that maltose binding protein–fused, full-length wild-type MxB purifies as oligomers and further self-assembles into helical arrays in physiological salt. Guanosine triphosphate (GTP), but not guanosine diphosphate, binding results in array disassembly, whereas subsequent GTP hydrolysis allows its reformation. Using cryo-electron microscopy (cryoEM), we determined the MxB assembly structure at 4.6 Å resolution, representing the first near-atomic resolution structure in the mammalian dynamin superfamily. The structure revealed previously described and novel MxB assembly interfaces. Mutational analyses demonstrated a critical role for one of the novel interfaces in HIV-1 restriction.en-USSciAdv r-articlesLife SciencesProteinsJournal Article2017-12-0510.1126/sciadv.1701264