Physical Structure and Expression ofalkBA Encoding Alkane Hydroxylase and Rubredoxin Reductase fromPseudomonas maltophilia

The structural genes of thePseudomonas maltophilia alksystem, which are localized on the OCT plasmid were cloned as a 4.2-kilobase pair Hind III fragment. This fragment contains sequences for alkane hydroxylase gene (alkB) and rubredoxin reductase gene (alkA), respectively. ThealkB gene encodes a 373-amino acid polypeptide (47.4 kD) that can be expressed at high levels inPseudomonasandEsherichia coli. ThealkBA genes were complemented with alkane hydroxylation in both bacteria. This result shows thatalkBA gene is essential for alkane hydroxylation since chromosomal loci have been encoded for other enzymes involved in fatty acid oxidation.