Redesign of the Phosphate Binding Site of L‐Rhamnulose‐ 1‐Phosphate Aldolase towards a Dihydroxyacetone Dependent Aldolase

Abstract

AbstractThe aldol addition of unphosphorylated dihydroxyacetone (DHA) to aldehydes catalyzed by L‐rhamnulose‐1‐phosphate aldolase (RhuA), a dihydroxyacetone phosphate‐dependent aldolase, is reported. Moreover, a single point mutation in the phosphate binding site of the RhuA wild type, that is, substitution of aspartate for asparagine at position N29, increased by 3‐fold the ${V{{app\hfill \atop {\rm max}\hfill}}}$ of aldol addition reactions of DHA to other aldehyde acceptors rather than the natural L‐lactaldehyde. The RhuA N29D mutant modified the optimum enzyme design for the natural substrate and changed its catalytic properties making the aldolase more versatile to other aldol additions of DHA.