3k1j

Publication Abstract from PubMed

Lon proteases are distributed in all kingdoms of life and are required for survival of cells under stress. Lon is a tandem fusion of an AAA+ molecular chaperone and a protease with a serine-lysine catalytic dyad. We report the 2.0-A resolution crystal structure of Thermococcus onnurineus NA1 Lon (TonLon). The structure is a three-tiered hexagonal cylinder with a large sequestered chamber accessible through an axial channel. Conserved loops extending from the AAA+ domain combine with an insertion domain containing the membrane anchor to form an apical domain that serves as a gate governing substrate access to an internal unfolding and degradation chamber. Alternating AAA+ domains are in tight- and weak-binding nucleotide states with different domain orientations and intersubunit contacts, reflecting intramolecular dynamics during ATP-driven protein unfolding and translocation. The bowl-shaped proteolytic chamber is contiguous with the chaperone chamber allowing internalized proteins direct access to the proteolytic sites without further gating restrictions.

Crystal structure of Lon protease: molecular architecture of gated entry to a sequestered degradation chamber.,Cha SS, An YJ, Lee CR, Lee HS, Kim YG, Kim SJ, Kwon KK, De Donatis GM, Lee JH, Maurizi MR, Kang SG EMBO J. 2010 Oct 20;29(20):3520-30. Epub 2010 Sep 10. PMID:20834233^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.