Identification of Escherichia coli K12 YdcW protein as a gamma-aminobutyraldehyde dehydrogenase.

Gamma-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. Km parameters of YdcW for gamma-aminobutyraldehyde, NAD+ and NADP+ were 41+/-7, 54+/-10 and 484+/-72 microM, 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 gamma-aminobutyric acid.