Pyruvate-dependent aldolases exhibit as tringent selectivity for pyruvate,l imiting application of their synthetic potential, which is ad rawback shared with other existing aldolases.S tructure-guided rational protein engineering rendered a2 -keto-3-deoxy-l-rhamnonate aldolase variant, fused with am altose-binding protein (MBP-YfaU W23V/L216A), capable of efficiently converting larger pyruvate analogues,for example,t hose with linear and branched aliphatic chains,i n aldol addition reactions.C ombination of these nucleophiles with N-Cbz-alaninal (Cbz = benzyloxycarbonyl) and N-Cbzprolinal electrophiles gave access to chiral building blocks,for example,d erivatives of (2S,3S,4R)-4-amino-3-hydroxy-2methylpentanoic acid (68 %, d.r.9 0:10) and the enantiomer of dolaproine (33 %, d.r.9 4:6) as well as ac ollection of unprecedented a-amino acid derivatives of the proline and pyrrolizidine type.C onversions varied between 6-93 %a nd diastereomeric ratios from 50:50 to 95:5 depending on the nucleophilic and electrophilic components.