Identification of Escherichia coli K12 YdcW protein as a γ‐aminobutyraldehyde dehydrogenase

Abstract
γ‐Aminobutyraldehyde dehydrogenase (ABALDH) from wild‐type E. coli K12 was purified to apparent homogeneity and identified as YdcW by MS‐analysis. YdcW exists as a tetramer of 202 ± 29 kDa in the native state, a molecular mass of one subunit was determined as 51 ± 3 kDa. K m parameters of YdcW for γ‐aminobutyraldehyde, NAD+ and NADP+ were 41 ± 7, 54 ± 10 and 484 ± 72 μM, respectively. YdcW is the unique ABALDH in E. coli K12. A coupling action of E. coli YgjG putrescine transaminase and YdcW dehydrogenase in vitro resulted in conversion of putrescine into γ‐aminobutyric acid.