A novel single-stranded DNA-specific 3'-5' exonuclease, Thermus thermophilus exonuclease I, is involved in several DNA repair pathways.

ABSTRACT: Single-stranded DNA (ssDNA)-specific exonucleases (ssExos) are expected to be involved in a variety of DNA repair pathways corresponding to their cleavage polarities; however, the relationship between the cleavage polarity and the respective DNA repair pathways is only partially understood. To understand the cellular function of ssExos in DNA repair better, genes encoding ssExos were disrupted in Thermus thermophilus HB8 that seems to have only a single set of 5'-3' and 3'-5' ssExos unlike other model organisms. Disruption of the tthb178 gene, which was expected to encode a 3'-5' ssExo, resulted in significant increase in the sensitivity to H(2)O(2) and frequency of the spontaneous mutation rate, but scarcely affected the sensitivity to ultraviolet (UV) irradiation. In contrast, disruption

SUBMITTER: Shimada A 

PROVIDER: S-EPMC2943613 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature