Open AccessEffects on IS 1 transposition frequency of a mutation in the ygjD gene involved in an essential t RNA modification in E scherichia coli
Author(s) -
Hashimoto Chika,
Hashimoto Masayuki,
Honda Hirofumi,
Kato Junichi
Publication year - 2013
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12227
Subject(s) - frameshift mutation , genetics , transposition (logic) , biology , mutant , transposase , gene , transposable element , insertion sequence , transfer rna , mutation , microbiology and biotechnology , insertion , rna , linguistics , philosophy
The Y gj D protein is essential for the synthesis of the universal t RNA modification, N 6 ‐threonylcarbamoyladenosine (t 6 A ), which is necessary for the decoding of ANN codons. We isolated a suppressor ( ygj D sup ) of the ygj D ts mutant by its permissive growth at high temperature in E scherichia coli . Resequencing of the ygj D sup mutant genome showed the presence of a complicated chromosome rearrangement, an inverse insertion of a large duplicated region ( c . 450 kb) into a small deleted region. The temperature‐resistant growth associated with ygj D sup was due to the presence of multicopy suppressor genes, yjeE and groL , of the ygj D ts mutation in the duplicated region. This DNA rearrangement was not simply mediated by IS 1 transposition, but the duplicated region was flanked by IS 1 . We showed that the frequency of IS 1 transposition was increased in ygj D ts mutants. The transposase of IS 1 is coded for by the insB gene, and its translation occurs through a frameshift of a ribosome translating upstream of the insA gene. We showed that this frameshifting frequency was increased by the ygj D ts mutation. These results indicated that the mutation of the gene for t RNA modification, t 6 A , affected IS 1 transposition.