Identification of the rhaA, rhaB and rhaD gene products from Escherichia coli K-12.

The three structural genes rhaA, rhaB and rhaD, that specify the enzymes rhamnose isomerase, rhamnulose kinase and rhamnulose 1-phosphate aldolase respectively, have been cloned from Escherichia coli K-12. The precise location of the genes has been determined by gene complementation analysis and by enzymatic assays of strains transformed with recombinant plasmids containing different parts of the cloned region. The corresponding gene products have been studied by their expression in maxicells. Protein products of 47 kDa, 52-54 kDa and 32 kDa have been assigned to rhamnose isomerase, rhamnulose kinase and rhamnulose 1-phosphate aldolase respectively.