Evolutionary bidirectional expansion for the tracing of alpha helices in cryo-electron microscopy reconstructions.

ABSTRACT: Cryo-electron microscopy (cryo-EM) enables the imaging of macromolecular complexes in near-native environments at resolutions that often permit the visualization of secondary structure elements. For example, alpha helices frequently show consistent patterns in volumetric maps, exhibiting rod-like structures of high density. Here, we introduce VolTrac (Volume Tracer) - a novel technique for the annotation of alpha-helical density in cryo-EM data sets. VolTrac combines a genetic algorithm and a bidirectional expansion with a tabu search strategy to trace helical regions. Our method takes advantage of the stochastic search by using a genetic algorithm to identify optimal placements for a short cylindrical template, avoiding exploration of already characterized tabu regions. These placements a

SUBMITTER: Rusu M 

PROVIDER: S-EPMC3288247 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature