Cloning and sequencing of two genes from Staphylococcus carnosus coding for glucose-specific PTS and their expression in Escherichia coli K-12

Abstract

Phosphoenolpyruvate (PEP)-dependent phosphorylation experiments have indicated that the gram-positive bacterium Staphylococcus carnosus possesses an EIICBA fusion protein specific for glucose. Here we report the cloning of a 7 kb genomic DNA fragment containing two genes, glcA and glcB, coding for the glucose-specific PTS transporters EII(Glc)1 and EII(Glc)2 which are 69% identical. The translation products derived from the nucleotide sequence consist of 675 and 692 amino acid residues and have calculated molecular weights of 73025 and 75256, respectively. Both genes can be stably maintained in Escherichia coli cells and restore the ability to ferment glucose to ptsG deletion mutants of E. coli. This demonstrates the ability of the PTS proteins HPr and/or EIIA(Glc) of a gram-negative organism (E. coli) to phosphorylate an EIICBA(Glc) from a gram-positive organism (S. carnosus).