Cover Picture: On the Importance of Anion–π Interactions in the Mechanism of Sulfide:Quinone Oxidoreductase (Chem. Asian J. 11/2013)

Abstract

The anion–π interaction is a well‐recognized noncovalent force that is established between electron‐deficient rings and anions. In the Communication by Antonio Frontera and co‐workers on , the relevance of this noncovalent interaction has been put on the scene by highlighting its critical role in the mechanism of sulfide:quinone oxidoreductase. In the first step of the enzymatic mechanism, an anionic intermediate is formed and is stabilized by an anion–π interaction that involves a cysteine residue and a flavin adenine dinucleotide (FAD) molecule. In the Cover picture, a dragon spits fireballs that represent the sulfur atoms of the two cysteine residues of the active site (disulfide bridge), of which one interacts with the FAD molecule placed on a branch.