Automatic cryo-EM particle selection for membrane proteins in spherical liposomes.

ABSTRACT: Random spherically constrained (RSC) single particle reconstruction is a method to obtain structures of membrane proteins embedded in lipid vesicles (liposomes). As in all single-particle cryo-EM methods, structure determination is greatly aided by reliable detection of protein "particles" in micrographs. After fitting and subtraction of the membrane density from a micrograph, normalized cross-correlation (NCC) and estimates of the particle signal amplitude are used to detect particles, using as references the projections of a 3D model. At each pixel position, the NCC is computed with only those references that are allowed by the geometric constraint of the particle's embedding in the spherical vesicle membrane. We describe an efficient algorithm for computing this position-dependent corre

SUBMITTER: Liu Y 

PROVIDER: S-EPMC3978669 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature