Frontispiece: Cation-π Interactions Contribute to Substrate Recognition in γ-Butyrobetaine Hydroxylase Catalysis

Biocatalysis γ‐Butyrobetaine hydroxylase (BBOX) contains an aromatic cage for the recognition of the positively charged trimethylammonium group of its γ‐butyrobetaine (γBB) substrate. Enyzme binding and kinetic analyses on substrate analogues with P and As substituting for N in the trimethylammonium group show that the analogues are good BBOX substrates, which follow the efficiency trend N+>P+>As+, but an uncharged carbon analogue of γBB is not a good BBOX substrate, thus highlighting the importance of energetically favorable cation–π interactions in productive substrate recognition. For more information, see the Full Paper from J. Mecinović et al. on page 1270 ff.