5WID

Structure of a flavodoxin from the domain Archaea

Summary for 5WID

• Entry DOI: 10.2210/pdb5wid/pdb
• Descriptor: Flavodoxin, FLAVIN MONONUCLEOTIDE, ACETATE ION, ... (5 entities in total)
• Functional Keywords: flavodoxin, methanosarcina acetivorans, flavoprotein
• Biological source: Methanosarcina acetivorans C2A
• Total number of polymer chains: 3
• Total formula weight: 50757.44

Authors

Murakami, K.S.,Ferry, J.G. (deposition date: 2017-07-19, release date: 2018-08-08, Last modification date: 2023-10-04)

Primary citation

Prakash, D.,Iyer, P.R.,Suharti, S.,Walters, K.A.,Santiago-Martinez, M.G.,Golbeck, J.H.,Murakami, K.S.,Ferry, J.G.
Structure and function of an unusual flavodoxin from the domainArchaea.
Proc.Natl.Acad.Sci.USA, 116:25917-25922, 2019

PubMed Abstract: Flavodoxins, electron transfer proteins essential for diverse metabolisms in microbes from the domain , are extensively characterized. Remarkably, although genomic annotations of flavodoxins are widespread in microbes from the domain , none have been isolated and characterized. Herein is described the structural, biochemical, and physiological characterization of an unusual flavodoxin (FldA) from , an acetate-utilizing methane-producing microbe of the domain In contrast to all flavodoxins, FldA is homodimeric, markedly less acidic, and stabilizes an anionic semiquinone. The crystal structure reveals an flavin mononucleotide (FMN) binding site unique from all other flavodoxins that provides a rationale for stabilization of the anionic semiquinone and a remarkably low reduction potentials for both the oxidized/semiquinone (-301 mV) and semiquinone/hydroquinone couples (-464 mV). FldA is up-regulated in acetate-grown versus methanol-grown cells and shown here to substitute for ferredoxin in mediating the transfer of low potential electrons from the carbonyl of acetate to the membrane-bound electron transport chain that generates ion gradients driving ATP synthesis. FldA offers potential advantages over ferredoxin by () sparing iron for abundant iron-sulfur proteins essential for acetotrophic growth and () resilience to oxidative damage.

PubMed: 31801875
DOI: 10.1073/pnas.1908578116

Experimental method

X-RAY DIFFRACTION (1.681 Å)