PACM Colloquium: Some solved and unsolved problems in single-particle cryo-EM

The determination of 3D protein structures by electron cryomicroscopy has been astonishingly successful in some cases, but quite unsuccessful in others. I will first discuss the status of our work on 3D structure determination of a membrane protein. Then, from the perspective of an experimentalist, I will describe some remaining problems with single-particle reconstruction that I hope might yield to mathematical solutions.