| Autor: |
Liu, Mu Ya, Gui, Gaojun, Wei, Bangdong, Preston, James F., Oakford, Lawrence, Yüksel, Ümit, Giedroc, David P., Romeo, Tony |
| Zdroj: |
Journal of Biological Chemistry; July 1997, Vol. 272 Issue: 28 p17502-17510, 9p |
| Abstrakt: |
The RNA-binding protein CsrA (carbon storage regulator) is a new kind of global regulator, which facilitates specific mRNA decay. A recombinant CsrA protein containing a metal-binding affinity tag (CsrA-H6) was purified to homogeneity and authenticated by N-terminal sequencing, matrix-assisted laser desorption/ionization time of flight mass spectrometry, and other studies. This protein was entirely contained within a globular complex of approximately 18 CsrA-H6 subunits and a single ∼350-nucleotide RNA, CsrB. cDNA cloning and nucleotide sequencing revealed that thecsrBgene is located downstream from sydin the 64-min region of the Escherichia coliK-12 genome and contains no open reading frames. The purified CsrA-CsrB ribonucleoprotein complex was active in regulating glg(glycogen biosynthesis) gene expression in vitro, as was the RNA-free form of the CsrA protein. Overexpression ofcsrBenhanced glycogen accumulation in E. coli, a stationary phase process that is repressed by CsrA. Thus, CsrB RNA is a second component of the Csr system, which binds to CsrA and antagonizes its effects on gene expression. A model for regulatory interactions in Csr is presented, which also explains previous observations on the homologous system in Erwinia carotovora. A highly repeated nucleotide sequence located within predicted stem-loops and other single-stranded regions of CsrB, CAGGA(U/A/C)G, is a plausible CsrA-binding element. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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