Projected structure of the surface protein of Deinococcus radiodurans determined to 8 Å resolution by cryomicroscopy

Cryomicroscopy at liquid nitrogen temperature has been used, in conjunction with correlation averaging, to determine the projection structure of the surface protein (HPI layer) of the Bacterium Deinococcus radiodurans to a resolution of 0.83 nm. The two-dimensional crystals were embedded in a thin layer of frozen-hydrated aurothioglucose, obtained by the controlled evaporation of an aurothioglucose solution and cryofixation in the syrup state. The relative merits of this preparation procedure are evaluated