Cloning and heterologous expression of a novel arylmalonate decarboxylase gene from Alcaligenes bronchisepticus KU 1201.

We have cloned and sequenced a DNA fragment that encodes the arylmalonate decarboxylase (AM-Dase) gene from Alcaligenes bronchisepticus KU 1201. The AMDase gene consists of an open reading frame of 720 nucleotides, which specifies a 240-amino-acid protein of relative molecular mass (M(r)) 24734. The M(r) deduced from the AMDase gene is in good agreement with that of the AMDase isolated from A. bronchisepticus. No TATA or TTGA sequence was observed within the cloned DNA fragment, but the fragment was expressed in Escherichia coli by the lac promoter of pUC19. The enzyme produced in E. coli has the same M(r) and the same enzyme activity as that purified from A. bronchisepticus. Comparison of the DNA sequence and the deduced amino acid sequence of AMDase with available DNA and amino acid sequence data bases revealed that there are no significant sequence homologies.