Previous Article | Next Article ![]()
J. Bacteriol., 11 1997, 6880-6886, Vol 179, No. 22
MC Menendez, JA Ainsa, C Martin and MJ Garcia
It has been suggested that catalase-peroxidase plays an important role in
several aspects of mycobacterial metabolism and is a virulence factor in
the main pathogenic mycobacteria. In this investigation, we studied genes
encoding for this protein in the fast-growing opportunistic pathogen
Mycobacterium fortuitum. Nucleotide sequences of two different
catalase-peroxidase genes (katGI and katGII) of M. fortuitum are described.
They show only 64% homology at the nucleotide level and 55% identity at the
amino acid level, and they are more similar to catalases-peroxidases from
different bacteria, including mycobacteria, than to each other. Both
proteins were found to be expressed in actively growing M. fortuitum, and
both could also be expressed when transformed into Escherichia coli and M.
aurum. We detected the presence of a copy of IS6100 in the neighboring
region of a katG gene in the M. fortuitum strain in which this element was
identified (strain FC1). The influence of each katG gene on isoniazid
(isonicotinic acid hydrazide; INH) susceptibility of mycobacteria was
checked by using the INH-sensitive M. aurum as the host. Resistance to INH
was induced when katGI was transformed into INH-sensitive M. aurum,
suggesting that this enzyme contributes to the natural resistance of M.
fortuitum to the drug. This is the first report showing two different genes
encoding same enzyme activity which are actively expressed within the same
mycobacterial strain.
Copyright © 1997, American Society for Microbiology
katGI and katGII encode two different catalases-peroxidases in Mycobacterium fortuitum
Departamento Medicina Preventiva, Facultad de Medicina, Universidad Autonoma de Madrid, Spain.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |