The origin of cardiac arrhythmias:
This animation shows what's known about the structure of the Ryanodine Receptor, a large protein that allows calcium ions to move from the endoplasmic reticulum to the cytoplasm. This calcium channel is of prime importance for the contraction of both cardiac and skeletal muscle. Mutations in the receptor can lead to genetic disease, including CPVT - an inherited cardiac disorder that can lead to cardiac arrhythmia and sudden cardiac death. Shown are 2 different levels of the structure: a low-resolution (~10 Angstrom) electron microscopy image of the entire receptor (white mesh), and a high-resolution (~2.5 Angstrom) crystal structure of the first ~550 amino acids. The high resolution portions corresponds to a 'hot spot' for disease mutations (indicated in red) in this calcium release channel. High-resolution crystal structures are excellent templates to generate new drugs that can interfere with the ryanodine receptor function in diseased states.
More info: http://crg.ubc.ca/VanPetegem/