Flavodoxins: sequence, folding, binding, function and beyond

Abstract

Flavodoxins are electron-transfer proteins involved in a variety of photosynthetic and non-photosynthetic reactions in bacteria, whereas, in eukaryotes, a descendant of the flavodoxin gene helps build multidomain proteins. The redox activity of flavodoxin derives from its bound flavin mononucleotide cofactor (FMN), whose intrinsic properties are profoundly modified by the host apoprotein. This review covers the very exciting last decade of flavodoxin research, in which the folding pathway, the structure and stability of the apoprotein, the mechanism of FMN recognition, the interactions that stabilize the functional complex and tailor the redox potentials, and many details of the binding and electron transfer to partner proteins have been revealed. The next decade should witness an even deeper understanding of the flavodoxin molecule and a greater comprehension of its many physiological roles. The fact that flavodoxin is essential for the survival of some human pathogens could make it a drug target on its own.

Review of NAD(P)H-dependent oxidoreductases: Properties, engineering and application

“…the NADP + -dependent ferredoxin oxidoreductase of some organisms are also able to catalyze redox reactions with flavodoxin (EC 1.19.1.1), another small, FMN-containing protein which participates in several redox reactions and can replace ferredoxin in some of its functions under low iron availability conditions [153]. This is the case, for example, of E. coli and Anabaena ferredoxin-NADP + reductase [49].…”

Genome-Guided Analysis of the Syntrophic Acetate Oxidizer <em>C. ultunense</em> and Comparative Genomics Reveal Different Strategies for Acetate Oxidation and Energy Conservation in Syntrophic Acetate-Oxidising Bacteria

“…The last redox carrier is very likely FMN, the redox potential of which strongly depends on the apoprotein [95]. The NQR complex might follow downstream of the RNF complex, both together forming a potential respiratory chain ( Figure 6).…”

Theoretical Analyses of Photoinduced Electron Transfer from Aromatic Amino Acids to the Excited Flavins in Some Flavoproteins

“…Flavodoxins are considered to function as electron-transport proteins in various metabolic pathways (Sancho, 2006). They contain one molecule of non covalently-bound FMN (see Chart 1) as a cofactor, and exhibit a highly negative reduction potential for the semiquinone / hydroquinone couple of FMN, and accordingly the semiquinone state is stable.…”