Cloning, characterisation, and expression of a novel gene encoding chlorite dismutase from Ideonella dechloratans

The gene for chlorite dismutase was isolated from a lambda ZAP genomic library of Ideonella dechloratans using peptide sequences obtained from the purified protein. A nucleotide sequence of 1200 bp was determined. The chlorite dismutase gene codes for a 285-residue polypeptide, with the experimentally determined N-terminus of the mature protein at residue 38. The N-terminal part of the encoded peptide has the characteristics of a signal sequence for periplasmic proteins. The nucleotide sequence and deduced protein showed no homology to sequences found in the databases. The transcriptional start point of the chlorite dismutase gene was determined with a new primer extension technique using capillary electrophoresis. Expression of recombinant chlorite dismutase in E. coli resulted in an active enzyme with similar spectral properties as the native enzyme.