New chemical crosslinking methods for the identification of transient protein-protein interactions with multiprotein complexes.

Most proteins function as multiprotein complexes or interact with multiprotein complexes. Identification of protein-protein interactions in the context of their physiologically relevant complexes is therefore key to fully understand the cellular machinery. Here I discuss advances in chemical crosslinking methods that allow investigators to map direct subunit contacts in transient interactions with multimeric complexes. Methods discussed fall into two categories: (i) in vitro approaches with localized, inducible crosslinking reagents and (ii) in vivo approaches with unlocalized crosslinkers.