The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
Gene Review

miaA  -  delta(2)-isopentenylpyrophosphate tRNA...

Escherichia coli str. K-12 substr. MG1655

Synonyms: ECK4167, JW4129, trpX
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of miaA


High impact information on miaA

  • The pheS,T operon is also derepressed in strains carrying a trpX mutation [5].
  • We show that the miaA mutator phenotype is dependent on recombination functions similar to, but not exactly the same as, those required for translation stress-induced mutagenesis [1].
  • Both the mutant isolated in this work and previously isolated miaA mutants confer tetracycline sensitivity in the presence of functional Tet(M), both share a slow growth phenotype, and in neither case is a wild-type phenotype restored in trans by F'112 carrying the 89- to 98-min region of the chromosome [6].
  • The function of the homologous gene in A. tumefaciens was proven by genetic complementation of E. coli miaA mutant strains. tRNA undermodification in A. tumefaciens miaA mutant strains may reduce vir gene expression by causing a reduced translation efficiency [3].
  • Insertions in miaA cause exclusively GC----TA transversions, which contrasts with the GC----AT and AT----GC transitions observed in mutL mutants [7].

Chemical compound and disease context of miaA


Biological context of miaA

  • miaA mutants, which contain A-37 instead of the ms(2)i(6)A-37 hypermodification in their tRNA, show a moderate mutator phenotype leading to increased GC-->TA transversion [1].
  • This structural arrangement confirms that miaA and mutL are in the same complex operon [7].
  • Three additional relationships were demonstrated between mutagenesis and the miaA gene or ms2i6A tRNA modification [8].
  • We speculate that miaD causes a decrease in ms2i6A-37 tRNA demodification or an increase in miaA gene expression but not at the level of operon transcription [7].
  • The miaA tRNA modification gene was cloned and located by insertion mutagenesis and DNA sequence analysis [8].

Associations of miaA with chemical compounds


Other interactions of miaA

  • Second, chromosomal miaA insertion mutations increased the spontaneous mutation frequency with a spectrum distinct from mutL mutations [8].
  • Instead, ppGpp is found to interfere with transcriptional readthrough in a manner which is dependent on the rpsL224, miaA, as well as the rpoB mutations [10].


  1. The miaA mutator phenotype of Escherichia coli K-12 requires recombination functions. Zhao, J., Leung, H.E., Winkler, M.E. J. Bacteriol. (2001) [Pubmed]
  2. Effects of mutations in the Pseudomonas putida miaA gene: regulation of the trpE and trpGDC operons in P. putida by attenuation. Olekhnovich, I., Gussin, G.N. J. Bacteriol. (2001) [Pubmed]
  3. Mutation of the miaA gene of Agrobacterium tumefaciens results in reduced vir gene expression. Gray, J., Wang, J., Gelvin, S.B. J. Bacteriol. (1992) [Pubmed]
  4. Molecular cloning of the Escherichia coli miaA gene involved in the formation of delta 2-isopentenyl adenosine in tRNA. Caillet, J., Droogmans, L. J. Bacteriol. (1988) [Pubmed]
  5. Escherichia coli phenylalanyl-tRNA synthetase operon is controlled by attenuation in vivo. Springer, M., Trudel, M., Graffe, M., Plumbridge, J., Fayat, G., Mayaux, J.F., Sacerdot, C., Blanquet, S., Grunberg-Manago, M. J. Mol. Biol. (1983) [Pubmed]
  6. tRNA modification activity is necessary for Tet(M)-mediated tetracycline resistance. Burdett, V. J. Bacteriol. (1993) [Pubmed]
  7. Structure of Escherichia coli K-12 miaA and characterization of the mutator phenotype caused by miaA insertion mutations. Connolly, D.M., Winkler, M.E. J. Bacteriol. (1991) [Pubmed]
  8. Genetic and physiological relationships among the miaA gene, 2-methylthio-N6-(delta 2-isopentenyl)-adenosine tRNA modification, and spontaneous mutagenesis in Escherichia coli K-12. Connolly, D.M., Winkler, M.E. J. Bacteriol. (1989) [Pubmed]
  9. Regulation of phenylalanine biosynthesis in Escherichia coli K-12: control of transcription of the pheA operon. Gowrishankar, J., Pittard, J. J. Bacteriol. (1982) [Pubmed]
  10. Functional interactions between translation, transcription and ppGpp in growing Escherichia coli. Faxén, M., Isaksson, L.A. Biochim. Biophys. Acta (1994) [Pubmed]
WikiGenes - Universities