Cells were thawed and resuspended in 1 % Buffer B (1 g cell pellet/ 5 mL) and lysed by sonication (1 s ON, 1 s OFF, 50 % amplitude, 10 min). Cell debris was removed by high speed centrifugation at 18000 rpm for 20 min. The lysate superantant was loaded onto 5 mL of Ni-NTA Agarose (Qiagen) and the column washed with 25 mL 1 % Buffer B, 6 % Buffer B to remove untagged proteins and finally 10 mL 100 % Buffer B to elute purified protein. Fractions corresponding to the peak at 280 nm were checked for purity by SDS-PAGE and pure fractions were concentrated by spin column (Vivaspin 20, 20 kDA cutoff GE Healthcare) and buffer exchanged into 100 mM phosphate buffer, pH 7, 0. General procedure for analytical scale biotransformations in the amination direction Analytical scale biotransformations were performed using the specified ketone (2.5 mM) and the relevant enzyme (20 or 100 µM) in 100 mM KPi buffer pH 7 with 20% DMSO containing 1 mM pyridoxal phosphate and 500 mM isopropyl amine. The reaction mixture was incubated for 24 h with shaking at 800 r.p.m. The reaction was quenched with 1 volume acetonitrile with precipitated protein removed by centrifugation (14,000g for 10 minutes) with the supernatant used for UPLC analysis. For chiral analysis, reactions were quenched by the addition of 100 μL of 5 M NaOH and extracted with EtOAc (250 μL x 3). The organic phase was dried over MgSO4 and analysed by normal-phase HPLC.