Summary: The gene of which complements the fumarase deficiency of a mutant when present in multiple copies, has been located at 93.5 min in the E. coli linkage map and its product has been identified as a polypeptide of 61 kDal. Four overlapping ColEl plasmids representing a continuous segment of 23.3 kb of bacterial DNA have been isolated from the Clarke-Carbon gene bank and the location of the gene relative to the restriction map and the adjacent operon has been defined. Hybridization studies have shown that the B gene is homologous to the gene, which complements the mutation in single and multi-copy situations, and encodes an analogous 61 kDal product formerly regarded as the fumarase. The hybridization studies also showed that the fumarase gene () is homologous to an independent gene, (formerly ), which lies adjacent to the gene at 35·5 min in the linkage map. The N-terminal sequences of the and products exhibit a 51% identity over 88 residues. It is possible that the and genes are fumarase structural genes of and , and that the gene may encode a differentially-regulated fumarase or be a positive regulator gene which is essential for the expression of (but not ). If so, the gene may encode a related enzyme or activator that can replace the function when amplified.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error