EMD-34003
Close-ring hexamer of the substrate-bound Lon protease with an S678A mutation
EMD-34003
Single-particle3.4 Å
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Map released: 25/10/2023
Last modified: 29/11/2023
Sample Organism:
Bos taurus,
Meiothermus taiwanensis
Sample: Close-ring hexamer of MtaLon-S678A in a substrate-engaged state
Fitted models: 7ypk (Avg. Q-score: 0.231)
Deposition Authors: Li S
,
Hsieh KY
,
Kuo CI,
Lee SH,
Ho MR
,
Wang CH
,
Zhang K
,
Chang CI
Sample: Close-ring hexamer of MtaLon-S678A in a substrate-engaged state
Fitted models: 7ypk (Avg. Q-score: 0.231)
Deposition Authors: Li S
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A 5+1 assemble-to-activate mechanism of the Lon proteolytic machine.
Li S
,
Hsieh KY
,
Kuo CI,
Lin TC,
Lee SH,
Chen YR
,
Wang CH
,
Ho MR
,
Ting SY,
Zhang K
,
Chang CI
(2023) Nat Commun , 14 , 7340 - 7340
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(2023) Nat Commun , 14 , 7340 - 7340
Abstract:
Many AAA+ (ATPases associated with diverse cellular activities) proteins function as protein or DNA remodelers by threading the substrate through the central pore of their hexameric assemblies. In this ATP-dependent translocating state, the substrate is gripped by the pore loops of the ATPase domains arranged in a universal right-handed spiral staircase organization. However, the process by which a AAA+ protein is activated to adopt this substrate-pore-loop arrangement remains unknown. We show here, using cryo-electron microscopy (cryo-EM), that the activation process of the Lon AAA+ protease may involve a pentameric assembly and a substrate-dependent incorporation of the sixth protomer to form the substrate-pore-loop contacts seen in the translocating state. Based on the structural results, we design truncated monomeric mutants that inhibit Lon activity by binding to the native pentamer and demonstrated that expressing these monomeric mutants in Escherichia coli cells containing functional Lon elicits specific phenotypes associated with lon deficiency, including the inhibition of persister cell formation. These findings uncover a substrate-dependent assembly process for the activation of a AAA+ protein and demonstrate a targeted approach to selectively inhibit its function within cells.
Many AAA+ (ATPases associated with diverse cellular activities) proteins function as protein or DNA remodelers by threading the substrate through the central pore of their hexameric assemblies. In this ATP-dependent translocating state, the substrate is gripped by the pore loops of the ATPase domains arranged in a universal right-handed spiral staircase organization. However, the process by which a AAA+ protein is activated to adopt this substrate-pore-loop arrangement remains unknown. We show here, using cryo-electron microscopy (cryo-EM), that the activation process of the Lon AAA+ protease may involve a pentameric assembly and a substrate-dependent incorporation of the sixth protomer to form the substrate-pore-loop contacts seen in the translocating state. Based on the structural results, we design truncated monomeric mutants that inhibit Lon activity by binding to the native pentamer and demonstrated that expressing these monomeric mutants in Escherichia coli cells containing functional Lon elicits specific phenotypes associated with lon deficiency, including the inhibition of persister cell formation. These findings uncover a substrate-dependent assembly process for the activation of a AAA+ protein and demonstrate a targeted approach to selectively inhibit its function within cells.