Structural?dynamics?is?important?in?enzymes?to?achieve?optimal?complementarity?to?the?activated?complex? of?the?catalyzed?reaction?and,?hence,?give?rise?to?rate?acceleration?and?(enantio)selectivity.?Here,?we?present? an? artificial? metalloenzyme? based? on? the? transcriptional? regulator? LmrR? that? exhibits? a? unique? form? of? structural?dynamics?involving?the?positioning?of?its?abiological?metal?cofactor.?The?position?of?the?cofactor,? in? turn,?was? found? to?be? related? to? the?preferred?catalytic? reactivity,?which?is?either? the?enantioselective? Friedel‐Crafts? alkylation? of? indoles? with? β‐substituted? enones? or? the? tandem? Friedel‐Crafts? alkylation? /? enantioselective?protonation?of?indoles?with?α?‐substituted?enones.?The?artificial?metalloenzyme?could?be? specialized?for?one?of?these?catalytic?reactions?by?introducing?a?single?mutation?in?the?protein.?The?switching? of?catalytic?activity?by?dynamic?interconversion?of?the?position?of?a?metal?cofactor?has?not?been?described?for? natural?enzymes?and,?to?date,?appears?to?be?unique?to?supramolecularly?assembled?artificial?metalloenzymes.?