PDBsum entry 3k1j

Hydrolase

PDB id: 3k1j

Contents

Protein chains

566 a.a.

Ligands

ADP ×2

PE8

PE4

Waters ×835

References listed in PDB file

Key reference

• Title: Crystal structure of lon protease: molecular architecture of gated entry to a sequestered degradation chamber.
• Authors: S.S.Cha, Y.J.An, C.R.Lee, H.S.Lee, Y.G.Kim, S.J.Kim, K.K.Kwon, G.M.De donatis, J.H.Lee, M.R.Maurizi, S.G.Kang.
• Ref.: Embo J, 2010, 29, 3520-3530.
• PubMed id: 20834233

Abstract

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-Å 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.