Time-lapse anomalous X-ray diffraction shows how Fe(2+) substrate ions move through ferritin protein nanocages to oxidoreductase sites.

ABSTRACT: Ferritin superfamily protein cages reversibly synthesize internal biominerals, Fe2O3·H2O. Fe(2+) and O2 (or H2O2) substrates bind at oxidoreductase sites in the cage, initiating biomineral synthesis to concentrate iron and prevent potentially toxic reactions products from Fe(2+)and O2 or H2O2 chemistry. By freezing ferritin crystals of Rana catesbeiana ferritin M (RcMf) at different time intervals after exposure to a ferrous salt, a series of high-resolution anomalous X-ray diffraction data sets were obtained that led to crystal structures that allowed the direct observation of ferrous ions entering, moving along and binding at enzyme sites in the protein cages. The ensemble of crystal structures from both aerobic and anaerobic conditions provides snapshots of the iron substrate bound at d

SUBMITTER: Pozzi C 

PROVIDER: S-EPMC4388269 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature