Disease relevance of mutT

• Characterization of the mutX gene of Streptococcus pneumoniae as a homologue of Escherichia coli mutT, and tentative definition of a catalytic domain of the dGTP pyrophosphohydrolases [1].
• The mutX gene of Streptococcus pneumoniae, a homologue of the Escherichia coli mutT mutator gene (Méjean, V., Salles, C., Bullions, L. C., Bessman, M. J., and Claverys, J.-P. (1993) Mol. Microbiol. 11, 323-330) has been cloned into an expression vector, and its gene product, the MutX protein, has been purified to apparent homogeneity [2].

High impact information on mutT

• The involvement of mismatch repair defects in microsatellite instability and tumorigenesis suggests that a generalized mutator phenotype is responsible for the large number of genetic alterations observed in tumors [3].
• Site-directed mutagenesis and analysis of nitrosoguanidine-induced mutT mutants suggest that a small region of high homology between the two proteins (61% identity over 23 residues) is part of the catalytic site of the nucleoside triphosphatase [1].
• Here we report that disrupting the pneumococcal mutY homologue abolishes the hyperrecombination induced by ami36 and leads to a mutator phenotype specifically enhancing AT-to-CG transversions [4].
• In agreement with this hypothesis, an increase in mutS gene copy number abolished the hexA-induced mutator phenotype [5].
• Fitness limitations of mutators may be overcome simply by the high bacterial cell densities that can be achieved during acute infection or by the adoption of transient mutator status [6].

Chemical compound and disease context of mutT

• We show that deletion of a gene of Streptococcus pneumoniae, which we call mutX, confers a mutator phenotype to resistance to streptomycin [1].

References