Non-heme Fe(II) Oxygenases: Structure-Reactivity Relationships

Enzymic non-heme iron centres are a key structure in O2 metabolism. Enzymes employ these active sites to perform a variety of complex reactions, e.g. cleavage of C-C bonds, regio- and stereoselective hydroxylations, decarboxylations or even bond formations. A common metal binding motif, a facial triad of either two histidines and one carboxylate or three histidines that form the metals primary coordination sphere was found to link these diverse enzymes to one big superfamily sharing the same catalytic concept: molecular oxygen is reduced by a metal-bound (co)substrate. But what do we need the enzyme for? How do the first and second coordination shells of iron affect the enzymes reactivity towards dioxygen? We want to investigate these questions by the mechanistic, computational and mutational analysis of catalytically distinct but structurally related non-heme iron dependent dioxygenases.