Macromolecular ab initio phasing enforcing secondary and tertiary structure.

ABSTRACT: Ab initio phasing of macromolecular structures, from the native intensities alone with no experimental phase information or previous particular structural knowledge, has been the object of a long quest, limited by two main barriers: structure size and resolution of the data. Current approaches to extend the scope of ab initio phasing include use of the Patterson function, density modification and data extrapolation. The authors' approach relies on the combination of locating model fragments such as polyalanine α-helices with the program PHASER and density modification with the program SHELXE. Given the difficulties in discriminating correct small substructures, many putative groups of fragments have to be tested in parallel; thus calculations are performed in a grid or supercomputer. The m

SUBMITTER: Millan C 

PROVIDER: S-EPMC4285884 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature