Direct metal recognition by guanine nucleotide-exchange factor in the initial step of the exchange reaction

The plant Rab5 GTPase homologue ARA7 in complex with its guanine nucleotide-exchange factor VPS9a was crystallized in the presence of GDP and Ca²⁺, representing an initial intermediate of the exchange reaction.

Structures of an ATP-independent Lon-like protease and its complexes with covalent inhibitors

The crystal structure of an ATP-independent LonC protease revealed a proteolytic chamber with two open axial pores. A LonC-specific N-­terminal coil tethers the AAA+ and protease domains together. Structures with covalent inhibitors bound to the proteolytic active sites provide mechanistic insights into the recognition of inhibitors and polypeptide substrates within the conserved Lon proteolytic chamber.