A crystal-clear interaction: relating neuroligin/neurexin complex structure to function at the synapse.

Neuronal circuits are maintained by homeostatic mechanisms controlling synapse maturation and signaling. Neuroligins (NLs) and neurexins (Nrxs) may regulate the fine balance between excitation and inhibition. In this issue of Neuron, Araç et al. and Fabrichny et al. define crystal structures of NLs bound to beta-Nrx, providing insights into their synaptic actions and clarifying structural defects associated with autism-linked mutations.