FIRST CHARACTERIZATION OF THE PHOSPHONOACETALDEHYDE HYDROLASE GENE OFPSEUDOMONAS-AERUGINOSA

The phnX gene encoding the phosphonoacetaldehyde hydrolase (phosphonat ase) from the Gram-negative bacterium Pseudomonas aeruginosa A237 has been cloned and its sequence determined. The open reading frame consis ts of 825 nucleotides specifying a protein of 275 amino acid residues corresponding to a predicted molecular weight of 29 929. The deduced a mino acid sequence of PhnX did not share significant amino acid sequen ce similarity with any other polypeptide. Expression of the phosphonoa cetaldehyde hydrolase coding sequence in Escherichia coli under contro l of the E. coli tac promoter resulted in the production of enzymatica lly active protein with an affinity constant similar to that of the ph osphonoacetaldehyde hydrolase purified from P. aeruginosa A237. This i s the first nucleic sequence report of the phosphonoacetaldehyde hydro lase, an enzyme involved in the carbon-phosphorus bond cleavage. (C) 1 997 Elsevier Science B.V.