Directly reconstructing principal components of heterogeneous particles from cryo-EM images.

ABSTRACT: Structural heterogeneity of particles can be investigated by their three-dimensional principal components. This paper addresses the question of whether, and with what algorithm, the three-dimensional principal components can be directly recovered from cryo-EM images. The first part of the paper extends the Fourier slice theorem to covariance functions showing that the three-dimensional covariance, and hence the principal components, of a heterogeneous particle can indeed be recovered from two-dimensional cryo-EM images. The second part of the paper proposes a practical algorithm for reconstructing the principal components directly from cryo-EM images without the intermediate step of calculating covariances. This algorithm is based on maximizing the posterior likelihood using the Expectatio

SUBMITTER: Tagare HD 

PROVIDER: S-EPMC4536832 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature