Why the Flavin Adenine Dinucleotide (FAD) Cofactor Needs To Be Covalently Linked to Complex II of the Electron-Transport Chain for the Conversion of FADH₂ into FAD.

ABSTRACT: A covalently bound flavin cofactor is predominant in the succinate-ubiquinone oxidoreductase (SQR; Complex II), an essential component of aerobic electron transport, and in the menaquinol-fumarate oxidoreductase (QFR), the anaerobic counterpart, although it is only present in approximately 10 % of the known flavoenzymes. This work investigates the role of this 8α-N3-histidyl linkage between the flavin adenine dinucleotide (FAD) cofactor and the respiratory Complex II. After parameterization with DFT calculations, classical molecular-dynamics simulations and quantum-mechanics calculations for Complex II:FAD and Complex II:FADH₂ , with and without the covalent bond, were performed. It was observed that the covalent bond is essential for the active-center arrangement of the FADH

SUBMITTER: Dourado DFAR 

PROVIDER: S-EPMC5969107 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature