Unknown

Dataset Information

0

Site-directed mutagenesis reveals a novel catalytic mechanism of Mycobacterium tuberculosis alkylhydroperoxidase C.


ABSTRACT: Mycobacterium tuberculosis alkylhydroperoxidase C (AhpC) belongs to the peroxiredoxin family, but unusually contains three cysteine residues in its active site. It is overexpressed in isoniazid-resistant strains of M. tuberculosis. We demonstrate that AhpC is capable of acting as a general antioxidant by protecting a range of substrates including supercoiled DNA. Active-site Cys to Ala mutants show that all three cysteine residues are important for activity. Cys-61 plays a central role in activity and Cys-174 also appears to be crucial. Interestingly, the C174A mutant is inactive, but double mutant C174/176A shows significant revertant activity. Kinetic parameters indicate that the C176A mutant is active, although much less efficient. We suggest that M. tuberculosis AhpC therefore belongs to a novel peroxiredoxin family and might follow a unique disulphide-relay reaction mechanism.

SUBMITTER: Chauhan R 

PROVIDER: S-EPMC1222857 | biostudies-other | 2002 Oct

REPOSITORIES: biostudies-other

Similar Datasets

| S-EPMC10244393 | biostudies-literature
| S-EPMC2888417 | biostudies-literature
| S-EPMC3820426 | biostudies-literature
| S-EPMC3853301 | biostudies-literature
| S-EPMC3762836 | biostudies-literature
| S-EPMC4438272 | biostudies-literature
| S-EPMC3697558 | biostudies-literature
| S-EPMC1147603 | biostudies-other
| S-EPMC1178011 | biostudies-literature
| S-EPMC4357238 | biostudies-literature