We are all depressed about science funding, here is the answer to our problems.

Anti-depressants are widely prescribed by medical doctors in the Western world in an attempt to fight depression. Recently two groups independently crystalized Na-amino acid carriers with desipramine. What is so cool about these atomic resolution pictures of drug binding is that the substrates are occluded, but the desipramine displaces the 2 water molecules that are in the normal occluded conformation, forcing a salt bridge to be installed. This salt bridge in turn blocks the transport catalytic cycle. So X-ray crystallography is useful after all? Reading these lovely papers certainly took my blues away.

LeuT-desipramine structure reveals how antidepressants block neurotransmitter reuptake.
Zhou, et al., Science (2007) 317:1387-1890. The pic is taken from their Figure 2.

Antidepressant binding site in a bacterial homologue of neurotransmitter transporters.
Singh, et al., Nature (2007) 448:952-956. see also Nature 437, 215–223 (2005) by the same group.