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The random-model method enables ab initio 3D reconstruction of asymmetric particles and determination of particle symmetry.

ABSTRACT: Model-based, 3D reconstruction techniques depend on reliable starting models. We present an extension of the random-model method (RMM) that allows the ab initio generation of suitable starting models directly from un-averaged, experimental images of asymmetric or symmetric particles. Therefore, the asymmetric RMM can also be used to determine point-group symmetry. The procedure is facilitated by the use of (a) variable angular step-sizes during iterative origin and orientation searches, (b) high numbers of particle images, and (c) highly defocused images. The method is inhibited by mixed-handedness orientation assignments and by particles with inconspicuous features. For symmetric particles, symmetric RMMs can overcome these deficiencies.

SUBMITTER: Sanz-Garcia E

PROVIDER: S-EPMC2885456 | biostudies-other | 2010 Aug

REPOSITORIES: biostudies-other

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The random-model method enables ab initio 3D reconstruction of asymmetric particles and determination of particle symmetry.

Sanz-García Eduardo E Stewart Aaron B AB Belnap David M DM

Journal of structural biology 20100328 2

Model-based, 3D reconstruction techniques depend on reliable starting models. We present an extension of the random-model method (RMM) that allows the ab initio generation of suitable starting models directly from un-averaged, experimental images of asymmetric or symmetric particles. Therefore, the asymmetric RMM can also be used to determine point-group symmetry. The procedure is facilitated by the use of (a) variable angular step-sizes during iterative origin and orientation searches, (b) high ...[more]

PMID: 20353825

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