5E44

Crystal structure of holo-FNR of A. fischeri

Summary for 5E44

• Entry DOI: 10.2210/pdb5e44/pdb
• Descriptor: FNR regulator, IRON/SULFUR CLUSTER, (4S)-2-METHYL-2,4-PENTANEDIOL (3 entities in total)
• Functional Keywords: labile dimer, transcription
• Biological source: Aliivibrio fischeri
• Total number of polymer chains: 1
• Total formula weight: 29811.39

Authors

Volbeda, A.,Fontecilla-Camps, J.C. (deposition date: 2015-10-05, release date: 2015-12-16, Last modification date: 2024-01-10)

Primary citation

Volbeda, A.,Darnault, C.,Renoux, O.,Nicolet, Y.,Fontecilla-Camps, J.C.
The crystal structure of the global anaerobic transcriptional regulator FNR explains its extremely fine-tuned monomer-dimer equilibrium.
Sci Adv, 1:e1501086-e1501086, 2015

PubMed 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.

PubMed: 26665177
DOI: 10.1126/sciadv.1501086

Experimental method

X-RAY DIFFRACTION (2.65 Å)