AN ARTIFICIAL BIFUNCTIONAL ENZYME, GAMMA-GLUTAMYL KINASE GAMMA-GLUTAMYL PHOSPHATE REDUCTASE, IMPROVES NACL TOLERANCE WHEN EXPRESSED IN ESCHERICHIA-COLI

An artificial bifunctional enzyme, gamma-glutamyl kinase/gamma-glutamy l phosphate reductase, was obtained by fusing the Escherichia coil gen es proA and proB. The proB gene was fused to the 5'-end of the proA ge ne with a linker encoding five amino acids. When expressed in E. coil enhanced intracellular concentrations of proline were observed. At 0.6 M NaCl the growth rates for the strain carrying the fusion enzyme and a control harbouring a plasmid encoding the wild-type enzymes were 32 0 and 530 min, respectively.