2.3 Å resolution cryo-EM structure of human p97 and mechanism of allosteric inhibition

p97 is a hexameric AAA ATPase that is an attractive target for cancer drug development. Here, we report cryo-EM structures for ADP-bound, full-length, hexameric wild-type p97 in the presence and absence of an allosteric inhibitor at resolutions of 2.3 Å and 2.4 Å, respectively. We also report cryo-EM structures at ~ 3.3 Å, 3.2 Å and 3.3 Å resolutions respectively, for three distinct, co-existing functional states of p97 with occupancies of 0, 1 or 2 molecules of ATPγS per protomer. A large corkscrew-like change in molecular architecture coupled with upward displacement of the N-domain is observed only when ATPγS is bound to both D1 and D2 domains. These cryo-EM structures establish the sequence of nucleotide-driven structural changes in p97 at atomic resolution. They also enable elucidation of the binding mode of an allosteric small molecule inhibitor to p97 and illustrate how inhibitor binding at the interface between D1 and D2 domains prevents propagation of the conformational changes necessary for p97 function

The Molecular Mechanism of HIV Entry

One of today’s greatest health challenges is stopping the spread of the Human Immunodeficiency Virus (HIV). HIV’s only surface protein is the envelope glycoprotein (Env), therefore Env is a major target for HIV intervention and treatment. The exact details of Env-mediated virus entry are still unclear. However, recent cryo-electron microscopy (cryo-EM) data have shed light on some of Env’s mechanism and 3D structure. Due to the wealth of 3D data from disparate sources, a comprehensive 3D model reflecting the most current understanding of Env was needed for use by the scientific community. An effective way of explaining this critical research to the lay audience was also needed. Cyro-EM and X-ray crystallography datasets were used to create a 3D model of Env. The known conformational changes that Env undergoes upon binding to its target receptors were animated, and plausible intermediate conformations were filled in based on steric restraints. A video tailored for the lay audience explaining Env’s role in HIV entry and incorporating the new model was created with a combination of 2D and 3D animation. The animation was then shown to researchers in order to evaluate its accuracy and individuals with no advanced biology experience in order to evaluate its engagingness and understandability. The animation created through this project reflects the most current understanding of how the Env mechanism works. Researchers who evaluated the animation appreciated the overall animation but readily identified the hypothetical portions and details that had been left out for the sake of the lay audience. The lay audience viewers found the animation understandable and interesting, and responded positively to the molecular mechanism being presented in the context of the cellular interactions and general biology of HIV. This animation and the feedback received provide a strong foundation toward improved methods of communicating molecular biology to the lay audience through visualization, as well as using a 3D model to inform ongoing research

The Molecular Mechanism of HIV Entry

One of today’s greatest health challenges is stopping the spread of the Human Immunodeficiency Virus (HIV). HIV’s only surface protein is the envelope glycoprotein (Env), therefore Env is a major target for HIV intervention and treatment. The exact details of Env-mediated virus entry are still unclear. However, recent cryo-electron microscopy (cryo-EM) data have shed light on some of Env’s mechanism and 3D structure. Due to the wealth of 3D data from disparate sources, a comprehensive 3D model reflecting the most current understanding of Env was needed for use by the scientific community. An effective way of explaining this critical research to the lay audience was also needed. Cyro-EM and X-ray crystallography datasets were used to create a 3D model of Env. The known conformational changes that Env undergoes upon binding to its target receptors were animated, and plausible intermediate conformations were filled in based on steric restraints. A video tailored for the lay audience explaining Env’s role in HIV entry and incorporating the new model was created with a combination of 2D and 3D animation. The animation was then shown to researchers in order to evaluate its accuracy and individuals with no advanced biology experience in order to evaluate its engagingness and understandability. The animation created through this project reflects the most current understanding of how the Env mechanism works. Researchers who evaluated the animation appreciated the overall animation but readily identified the hypothetical portions and details that had been left out for the sake of the lay audience. The lay audience viewers found the animation understandable and interesting, and responded positively to the molecular mechanism being presented in the context of the cellular interactions and general biology of HIV. This animation and the feedback received provide a strong foundation toward improved methods of communicating molecular biology to the lay audience through visualization, as well as using a 3D model to inform ongoing research