AN EXPRESSION SYSTEM COMPRISING OPERABLY LINKED RGG GENE AND GTFG PROMOTER

摘要

Provided is a plasmid-based expression system that can be used to enhance production of C-repeat region (CRR) by Streptococcus gordonii, other Strpetococcus strains, as well as other bacteria. This system utilizes the gtfG promoter and secretion-signal sequence in combination with the positive regulatory gene, rgg, to drive the synthesis and secretion of CRR from the resident Escherichia. coli or Streptococcus shuttle plasmid, pVA838. This plasmid isolated from E. coli was readily introduced into S. gordonii and under optimal conditions led to a nearly 10-fold increase in the concentration of secreted protein relative to production by surface protein expression system (SPEX).