A standardized technique for high-pressure cooling of protein crystals.

Cryogenic temperatures slow down secondary radiation damage during data collection from macromolecular crystals. In 1973, cooling at high pressure was identified as a method for cryopreserving crystals in their mother liquor [Thomanek et al. (1973).

Toward visualization of nanomachines in their native cellular environment.

The cellular nanocosm is made up of numerous types of macromolecular complexes or biological nanomachines. These form functional modules that are organized into complex subcellular networks. Information on the ultra-structure of these nanomachines has mainly been obtained by analyzing isolated structures, using imaging techniques such as X-ray crystallography, NMR, or single particle electron microscopy (EM).

Membrane contact sites between apicoplast and ER in Toxoplasma gondii revealed by electron tomography.

Toxoplasma gondii is an obligate intracellular parasite from the phylum Apicomplexa. A hallmark of these protozoans is the presence of a unique apical complex of organelles that includes the apicoplast, a plastid acquired by secondary endosymbiosis. The apicoplast is indispensible for parasite viability.

A novel dynamin-related protein has been recruited for apicoplast fission in Toxoplasma gondii.

Background: Apicomplexan parasites cause numerous important human diseases, including malaria and toxoplasmosis. Apicomplexa belong to the Alveolata, a group that also includes ciliates and dinoflagellates. Apicomplexa retain a plastid organelle (the apicoplast) that was derived from an endosymbiotic relationship between the alveolate ancestor and a red alga.

Toxoplasma gondii Tic20 is essential for apicoplast protein import.

Apicomplexan parasites harbor a secondary plastid that has lost the ability to photosynthesize yet is essential for the parasite to multiply and cause disease. Bioinformatic analyses predict that 5-10% of all proteins encoded in the parasite genome function within this organelle. However, the mechanisms and molecules that mediate import of such large numbers of cargo proteins across the four membranes surrounding the plastid remain elusive.

New comprehension of the apicoplast of Sarcocystis by transmission electron tomography.

Background Information: Apicomplexan parasites (like Plasmodium, Toxoplasma, Eimeria and Sarcocystis) contain a distinctive organelle, the apicoplast, acquired by a secondary endosymbiotic process analogous to chloroplasts and mitochondria. The apicoplast is essential for long-term survival of the parasite. This prokaryotic origin implies that molecular and metabolic processes in the apicoplast differ from those of the eukaryotic host cells and therefore offer options for specific chemotherapeutic treatment.