IUCr journals

Structures of the SEp22 dodecamer, a Dps-like protein from Salmonella enterica subsp. enterica serovar Enteritidis

Acta Cryst. (2011). F67, 17-22 (doi.org/10.1107/S1744309110043113)

[Asp channel] An Mg2+ ion at the entrance of the Asp channel. The threefold axis of the octahedrally hydrated Mg2+ ion is almost coincident with the threefold axis at the Asp channel.

SEp22 from Salmonella enterica prevents the production of the reactive oxygen species (ROS) by sequestering FeII ions into the cavity of the dodecameric shell with 23 symmetry. The anti-ROS activity is crucial for the survival of S. enterica infection in humans. Structures of SEp22 dodecamers revealed the distorted octahedral geometry of FeII ions at the ferroxidase centers in high detail. Hydrated Mg2+ ions were located near the entrances of the Asp channels, which suggests how FeII ions pass through the channels and flow into the cavity.

T. Miyamoto, Y. Asahina, S. Miyazaki, H. Shimizu, U. Ohto, S. Noguchi and Y. Satow