Am. J. Respir. Crit. Care Med.,
Volume 156, Number 6, December 1997, 1993-1998
Development of a Suicide Gene as a Novel Approach
to Killing Mycobacterium tuberculosis
WILLIAM N.
ROM,
TING-AN
YIE,
and
KAM-MENG
TCHOU-WONG
Division of Pulmonary and Critical Care Medicine, Departments of Medicine, Environmental Medicine, and Microbiology,
New York University Medical Center, New York City, New York
The increase in multidrug-resistant tuberculosis and high mortality among those co-infected with
HIV-1 necessitates new therapeutic approaches directed at Mycobacterium tuberculosis. We hypothesized that a dominant-negative mutation in the DNA-dependent RNA polymerase gene would inhibit
transcription of all genes by blocking access of the wild-type enzyme to promoters. An evolutionarily
invariant lysine was substituted with arginine by site-directed mutagenesis in the rpoB gene. The
dominant-negative rpoB gene product inhibited a transposon-derived kanamycin-resistance gene in
both M. smegmatis and M. tuberculosis H37Rv, leading to growth inhibition of the mycobacteria on
solid media containing kanamycin. The dominant-negative mutant rpoB gene is a potential suicide
gene especially for the treatment of multidrug-resistant tuberculosis once a delivery strategy is also
developed.
