Conformational Flexibility of Ubiquitin-Modified and SUMO-Modified PCNA Shown by Full-Ensemble Hybrid Methods.

ABSTRACT: Ubiquitin-modified proliferating cell nuclear antigen (PCNA) and small ubiquitin-like modifier (SUMO)-modified PCNA regulate DNA damage tolerance pathways. X-ray crystal structures of these proteins suggested that they do not have much conformational flexibility because the modifiers have preferred binding sites on the surface of PCNA. By contrast, small-angle X-ray scattering analyses of these proteins suggested that they have different degrees of conformational flexibility, with SUMO-modified PCNA being more flexible. These conclusions were based on minimal-ensemble hybrid approaches, which produce unrealistic models by representing flexible proteins with only a few static structures. To overcome the limitations of minimal-ensemble hybrid approaches and to determine the degree of conform

SUBMITTER: Powers KT 

PROVIDER: S-EPMC6453135 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature