Disease relevance of nth

• The nth gene of Escherichia coli affects the production of endonuclease III, a glycosylase-endonuclease that attacks DNA damaged by oxidizing agents or by ionizing radiation [1].

High impact information on nth

• Mutants of Escherichia coli and mice (ref. 4 and M. Takao et al., personal communication) that are deficient in DNA glycosylases that remove oxidized bases are not sensitive to reactive oxygen species, and the E. coli triple mutant nei, nth, fpg is more radioresistant than the wild-type strain [2].
• The fpg gene is different from the xth, nth, and nfo genes of E. coli, whose gene products also cleave DNA at AP sites [3].
• Inspection of the nucleotide sequence reveals that there is an open reading frame immediately upstream of the nth gene, suggesting that it might be part of an operon [4].
• A strong chronic induction of the SOS response system occurs in E. coli BW535, a strain defective in nth, nfo and xth genes, and hence severely deficient in the repair of abasic sites in DNA [5].
• A triple mutant strain (nth nfo xthA) exhibited the greatest sensitivity to near-UV-mediated lethality [6].

Biological context of nth

• The nth operon has transcription initiation sites upstream of the first and second open reading frames and a single transcript termination site downstream of nth [7].
• The genes encoding these proteins, nei and nth, are both co-transcribed as the terminal genes in operons. nei is the terminal gene in an operon with four open reading frames that encode proteins of unknown function [7].
• The introduction of a plasmid carrying the nth, nei, or mutM gene into the E. coli triple mutant restored the formation of the corresponding protein-DNA complex [8].
• An Arabidopsis thaliana cDNA was isolated by complementation of the Escherichia coli mutant strain BW535 (xth, nfo, nth), which is defective in DNA base excision repair pathways [9].
• In contrast to nth mutants, which showed a weak mutator phenotype, nei single mutants behaved as the wild type [10].

Other interactions of nth

• This operon has two confirmed transcription initiation sites upstream of the first open reading frame and two transcript termination sites downstream of nei. nth is the terminal gene in an operon with seven open reading frames that encode proteins of unknown function [7].

References