SEQUENCE-ANALYSIS OF THE GENE ENCODING A NOVEL L-2,4-DIAMINOBUTYRATE DECARBOXYLASE OF ACINETOBACTER-BAUMANNII - SIMILARITY TO THE GROUP-II AMINO-ACID DECARBOXYLASES

The gene (ddc) encoding a novel enzyme, L-2,4-diaminobutyrate decarbox ylase (DABA-DC; EC 4.1.1-) in Acinetobacter baumannii was sequenced, a nd an open reading frame of 1,530 nucleotides was detected. The sequen ce of 20 N-terminal amino acids of purified DABA-DC and of its proteol ytic peptide fragments coincided with those deduced from the nucleotid e sequence determined. Comparison of the predicted amino acid sequence of the A. baumannii enzyme with those of other pyridoxal 5'-phosphate -dependent decarboxylases revealed significant similarity to the group II amino acid decarboxylases and conservation of the group II amino a cid decarboxylases and conservation of the putative pyridoxal 5'-phosp hate-binding domain.