7FD4

A complete three-dimensional structure of the Lon protease translocating a protein substrate (conformation 1)

Summary for 7FD4

• Entry DOI: 10.2210/pdb7fd4/pdb
• EMDB information: 31534
• Descriptor: Lon protease, Alpha-S1-casein, PHOSPHOTHIOPHOSPHORIC ACID-ADENYLATE ESTER, ... (5 entities in total)
• Functional Keywords: aaa+ protease, lon, complete three-dimensional structure, n-terminal domain, cytosolic protein, hydrolase-protein binding complex, hydrolase/protein binding
• Biological source: Meiothermus taiwanensis; More
• Total number of polymer chains: 7
• Total formula weight: 538674.79

Authors

Li, S.,Hsieh, K.,Kuo, C.,Lee, S.,Pintilie, G.,Zhang, K.,Chang, C. (deposition date: 2021-07-16, release date: 2021-11-03)

Primary citation

Li, S.,Hsieh, K.Y.,Kuo, C.I.,Lee, S.H.,Pintilie, G.D.,Zhang, K.,Chang, C.I.
Complete three-dimensional structures of the Lon protease translocating a protein substrate.
Sci Adv, 7:eabj7835-eabj7835, 2021

PubMed Abstract: Lon is an evolutionarily conserved proteolytic machine carrying out a wide spectrum of biological activities by degrading misfolded damaged proteins and specific cellular substrates. Lon contains a large N-terminal domain and forms a hexameric core of fused adenosine triphosphatase and protease domains. Here, we report two complete structures of Lon engaging a substrate, determined by cryo–electron microscopy to 2.4-angstrom resolution. These structures show a multilayered architecture featuring a tensegrity triangle complex, uniquely constructed by six long N-terminal helices. The interlocked helix triangle is assembled on the top of the hexameric core to spread a web of six globular substrate-binding domains. It serves as a multipurpose platform that controls the access of substrates to the AAA+ ring, provides a ruler-based mechanism for substrate selection, and acts as a pulley device to facilitate unfolding of the translocated substrate. This work provides a complete framework for understanding the structural mechanisms of Lon.

PubMed: 34652947
DOI: 10.1126/sciadv.abj7835

Experimental method

ELECTRON MICROSCOPY (2.4 Å)