Construction of a Mycobacterium - Escherichia coli Shuttle Vector and Use in the Expression of Foreign Genes in Mycobacteria

ABSTRACT

The ability to introduce recombinant DNA molecules back into mycobacteria would greatly increase the potential of molecular genetic approaches for the study of mycobacteria as well as for the use in clinical purposes. We have initiated the construction of vectors that facilitates the introduction of recombinant DNA into mycobacteria. The vector was designed to contain replicons for multiplication in mycobacteria and Escherichia coli, a promoter for gene expression, a drug resistant gene for selecting transformants, and a few restriction enzyme sites for convenient cloning. Constructed Mycobacterium-E. coli shuttle vector named p YMC (hsp60) was shown to transform M. smegmatis at high efficiency and maintain plasmid at stable level. The ability of the vector to express cloned foreign gene was also monitored by measuring the expressed level of luciferase gene which was used as a reporter. High level of luciferase activity in M. smegmatis with pYMC (hsp60luc) was detected confirming successful construction of Mycobacterium-E. coli shuttle vector.