New "Nature" paper on molecular mechanism of transmitter release

I mentioned in class that transmitter release is mediated by 2 key molecules (or more exactly, types of molecule), the SNARES and synaptotagmin. SNARES are protein that bring the vesicle membrane and the presynaptic plasma membrane together at the active zone (where release occurs). The new paper ( Nature, 525, 62–67, 03 September 2015) describes an X-ray crystalographic study of the interface between the calcium-detecting molecule synaptotagmin (on the vesicle membrane) and the SNARES, which are anchored in both vesicle and plasma membranes, and come together in the narrow space between them to form a "helix bundle". When calcium binds to the synaptotagmin it, via its interface with the SNARES, triggers a contraction of the helix bundle pulling the 2 membranes together and then dragging them so they actually fuse. Here's the key diagram from the paper (which the Nature robot might censor, but you can also look at online at the University library); look particularly at parts c,d and e.

Of course one always knew, since Katz's seminal discovery of the role of calcium in transmitter release,  that the underlying molecular machinery would eventually be mapped out, but it's still very satisfying to see all the details falling into place. Sudhof, one of the authors of the new paper, had already received the 2013 Nobel Prize for his work (with Rothman and Scheckman) for his work on the molecular mechanism of exocytosis.