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

dksA  -  transcriptional regulator of rRNA...

Escherichia coli str. K-12 substr. MG1655

Synonyms: ECK0144, JW0141, msmA
 
 

DksA does not interact directly with DNA, but rather with RNA polymerase (RNAP). DksA (mnemonic for dnaK suppressor) was originally discovered as a dosage dependent (multi-copy) suppressor of the temperature sensitivity phenotype of in an E. coli dnaK deletion mutant [1]. Paul et al. stated that deletion and overexpression of dksA have pleiotropic effects, including defects in chaperonin function, gene expression, cell division, amino acid biosynthesis, quorum sensing and virulence [2]. However, the molecular mechanisms linking dksA and these phenotypes had not been elucidated at that time. DksA works with ppGpp to regulate transcription of rRNA and amino acid promoters. ppGpp + DksA have differential effects at promoters recognized by sigma 70 (housekeeping) family RNA polymerase sigma factors: a) they decrease transcription initiation at rRNA promoters because they further destabilize already unstable open complexes, whereas b) they increase transcription initiation at aa biosynthesis promoters because they increase the rate of open complex formation of these already stable open complexes. These two factors also generally increase transcription from promoters recognized by alternative sigma factors (e.g. RpoN, RpoS, RpoH, RpoE ) [3][4].

 

 

Disease relevance of dksA

  • Inhibition of quorum sensing by a Pseudomonas aeruginosa dksA homologue [5].
  • The yadB gene is expressed in wild-type E. coli as an operon with the dksA gene, which encodes a protein involved in the general stress response by means of its action at the translational level [6].
  • dksA is required for intercellular spread of Shigella flexneri via an RpoS-independent mechanism [7].
 

High impact information on dksA

 

Biological context of dksA

  • Sequenced spontaneous extragenic suppressors of dksA polyauxotrophy are frequently the same T563P rpoB allele that suppresses a ppGpp(0) phenotype [11] .
  • DNA sequence analysis and in vivo experiments showed that dksA encodes a 17,500-Mr polypeptide [12].
  • Gene disruption experiments indicated that dksA is not an essential [12].
 

Other interactions of dksA

References

  1. Identification and characterization of a new Escherichia coli gene that is a dosage-dependent suppressor of a dnaK deletion mutation. Kang, P.J., Craig, E.A. J. Bacteriol. (1990) [Pubmed]
  2. DksA: a critical component of the transcription initiation machinery that potentiates the regulation of rRNA promoters by ppGpp and the initiating NTP. Paul, B.J., Barker, M.M., Ross, W., Schneider, D.A., Webb, C., Foster, J.W., Gourse, R.L. Cell. (2004) [Pubmed]
  3. Transcriptional switching in Escherichia coli during stress and starvation by modulation of sigma activity. Sharma, U.K., Chatterji, D. FEMS. Microbiol. Rev. (2010) [Pubmed]
  4. Control of bacterial transcription, translation and replication by (p)ppGpp. Srivatsan, A., Wang, J.D. Curr. Opin. Microbiol. (2008) [Pubmed]
  5. Inhibition of quorum sensing by a Pseudomonas aeruginosa dksA homologue. Branny, P., Pearson, J.P., Pesci, E.C., Köhler, T., Iglewski, B.H., Van Delden, C. J. Bacteriol. (2001) [Pubmed]
  6. An aminoacyl-tRNA synthetase-like protein encoded by the Escherichia coli yadB gene glutamylates specifically tRNAAsp. Dubois, D.Y., Blaise, M., Becker, H.D., Campanacci, V., Keith, G., Giegé, R., Cambillau, C., Lapointe, J., Kern, D. Proc. Natl. Acad. Sci. U.S.A. (2004) [Pubmed]
  7. dksA is required for intercellular spread of Shigella flexneri via an RpoS-independent mechanism. Mogull, S.A., Runyen-Janecky, L.J., Hong, M., Payne, S.M. Infect. Immun. (2001) [Pubmed]
  8. The transcription factor DksA prevents conflicts between DNA replication and transcription machinery. Tehranchi, A.K., Blankschien, M.D., Zhang, Y., Halliday, J.A., Srivatsan, A., Peng, J., Herman, C., Wang, J.D. Cell. (2010) [Pubmed]
  9. DksA: a critical component of the transcription initiation machinery that potentiates the regulation of rRNA promoters by ppGpp and the initiating NTP. Paul, B.J., Barker, M.M., Ross, W., Schneider, D.A., Webb, C., Foster, J.W., Gourse, R.L. Cell (2004) [Pubmed]
  10. DksA potentiates direct activation of amino acid promoters by ppGpp. Paul, B.J., Berkmen, M.B., Gourse, R.L. Proc. Natl. Acad. Sci. U.S.A. (2005) [Pubmed]
  11. DksA affects ppGpp induction of RpoS at a translational level. Brown, L., Gentry, D., Elliott, T., Cashel, M. J. Bacteriol. (2002) [Pubmed]
  12. Identification and characterization of a new Escherichia coli gene that is a dosage-dependent suppressor of a dnaK deletion mutation. Kang, P.J., Craig, E.A. J. Bacteriol. (1990) [Pubmed]
  13. A suppressor of mutations in the region adjacent to iterons of pSC101 ori. Ohkubo, S., Yamaguchi, K. J. Bacteriol. (1997) [Pubmed]
 
WikiGenes - Universities