EMD-22289
cross-reference map for CueR-TAC
EMD-22289
Single-particle4.1 Å
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Map released: 14/04/2021
Last modified: 28/07/2021
Sample Organism:
Escherichia coli
Sample: cross-reference map for CueR-TAC
Deposition Authors: Liu B, Shi W, Yang Y
Sample: cross-reference map for CueR-TAC
Deposition Authors: Liu B, Shi W, Yang Y
Structural basis of copper-efflux-regulator-dependent transcription activation.
Shi W
,
Zhang B,
Jiang Y,
Liu C,
Zhou W
,
Chen M,
Yang Y,
Hu Y,
Liu B
(2021) Iscience , 24 , 102449 - 102449
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(2021) Iscience , 24 , 102449 - 102449
Abstract:
The copper efflux regulator (CueR), a representative member of mercury resistance regulator (MerR) family metalloregulators, controls expression of copper homeostasis-regulating genes in bacteria. The mechanism of transcription activation by CueR and other MerR family regulators is bending the spacer domain of promoter DNA. Here, we report the cryo-EM structures of the intact CueR-dependent transcription activation complexes. The structures show that CueR dimer bends the 19-bp promoter spacer to realign the -35 and -10 elements for recognition by σ70-RNA polymerase holoenzyme and reveal a previously unreported interaction between the DNA-binding domain (DBD) from one CueR subunit and the σ70 nonconserved region (σNCR). Functional studies have shown that the CueR-σNCR interaction plays an auxiliary role in CueR-dependent transcription, assisting the activation mechanism of bending promoter DNA by CueR dimer. Because DBDs are highly conserved in sequence and structure, this transcription-activating mechanism could be generally used by MerR family regulators.
The copper efflux regulator (CueR), a representative member of mercury resistance regulator (MerR) family metalloregulators, controls expression of copper homeostasis-regulating genes in bacteria. The mechanism of transcription activation by CueR and other MerR family regulators is bending the spacer domain of promoter DNA. Here, we report the cryo-EM structures of the intact CueR-dependent transcription activation complexes. The structures show that CueR dimer bends the 19-bp promoter spacer to realign the -35 and -10 elements for recognition by σ70-RNA polymerase holoenzyme and reveal a previously unreported interaction between the DNA-binding domain (DBD) from one CueR subunit and the σ70 nonconserved region (σNCR). Functional studies have shown that the CueR-σNCR interaction plays an auxiliary role in CueR-dependent transcription, assisting the activation mechanism of bending promoter DNA by CueR dimer. Because DBDs are highly conserved in sequence and structure, this transcription-activating mechanism could be generally used by MerR family regulators.