PDBsum entry 5e44

Transcription

PDB id: 5e44

Contents

Protein chain

230 a.a.

Ligands

SF4

MPD ×2

PDB id:

5e44

Name:

Transcription

Title:

Crystal structure of holo-fnr of a. Fischeri

Structure:

Fnr regulator. Chain: a. Fragment: unp residues 3-250. Synonym: fumarate and nitrate reduction regulatory protein. Engineered: yes

Source:

Aliivibrio fischeri. Organism_taxid: 668. Gene: fnr. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

2.65Å R-factor: 0.190 R-free: 0.242

Authors:

A.Volbeda,J.C.Fontecilla-Camps

Key ref:

A.Volbeda et al. (2015). The crystal structure of the global anaerobic transcriptional regulator FNR explains its extremely fine-tuned monomer-dimer equilibrium. Sci Adv, 1, e1501086. PubMed id: 26665177 DOI: 10.1126/sciadv.1501086

Date:

05-Oct-15 Release date: 16-Dec-15

Protein chain

Q70ET4  (Q70ET4_ALIFS) -  FNR type regulator from Aliivibrio fischeri

Seq: 250 a.a.

Struc: 230 a.a.

DOI no: 10.1126/sciadv.1501086

Sci Adv 1:e1501086 (2015)

PubMed id: 26665177

The crystal structure of the global anaerobic transcriptional regulator FNR explains its extremely fine-tuned monomer-dimer equilibrium.

A.Volbeda, C.Darnault, O.Renoux, Y.Nicolet, J.C.Fontecilla-Camps.

ABSTRACT

The structure of the dimeric holo-fumarate and nitrate reduction regulator (FNR) from Aliivibrio fischeri has been solved at 2.65 Å resolution. FNR globally controls the transition between anaerobic and aerobic respiration in facultative anaerobes through the assembly/degradation of its oxygen-sensitive [4Fe-4S] cluster. In the absence of O2, FNR forms a dimer and specifically binds to DNA, whereas in its presence, the cluster is degraded causing FNR monomerization and DNA dissociation. We have used our crystal structure and the information previously gathered from numerous FNR variants to propose that this process is governed by extremely fine-tuned interactions, mediated by two salt bridges near the amino-terminal cluster-binding domain and an "imperfect" coiled-coil dimer interface. [4Fe-4S] to [2Fe-2S] cluster degradation propagates a conformational signal that indirectly causes monomerization by disrupting the first of these interactions and unleashing the "unzipping" of the FNR dimer in the direction of the carboxyl-terminal DNA binding domain.