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Essential ribosome assembly factor Fap7 regulates a hierarchy of RNA-protein interactions during small ribosomal subunit biogenesis.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2013 Sep 17; Vol. 110 (38), pp. 15253-8. Date of Electronic Publication: 2013 Sep 03. - Publication Year :
- 2013
-
Abstract
- Factor activating Pos9 (Fap7) is an essential ribosome biogenesis factor important for the assembly of the small ribosomal subunit with an uncommon dual ATPase and adenylate kinase activity. Depletion of Fap7 or mutations in its ATPase motifs lead to defects in small ribosomal subunit rRNA maturation, the absence of ribosomal protein Rps14 from the assembled subunit, and retention of the nascent small subunit in a quality control complex with the large ribosomal subunit. The molecular basis for the role of Fap7 in ribosome biogenesis is, however, not yet understood. Here we show that Fap7 regulates multiple interactions between the precursor rRNA, ribosomal proteins, and ribosome assembly factors in a hierarchical manner. Fap7 binds to Rps14 with a very high affinity. Fap7 binding blocks both rRNA-binding elements of Rps14, suggesting that Fap7 inhibits premature interactions of Rps14 with RNA. The Fap7/Rps14 interaction is modulated by nucleotide binding to Fap7. Rps14 strongly activates the ATPase activity but not the adenylate kinase activity of Fap7, identifying Rps14 as an example of a ribosomal protein functioning as an ATPase-activating factor. In addition, Fap7 inhibits the RNA cleavage activity of Nob1, the endonuclease responsible for the final maturation step of the small subunit rRNA, in a nucleotide independent manner. Thus, Fap7 may regulate small subunit biogenesis at multiple stages.
- Subjects :
- Amino Acid Sequence
Biophysics
Chromatography, Gel
Chromatography, Thin Layer
Circular Dichroism
Fluorescence Polarization
Magnetic Resonance Spectroscopy
Molecular Sequence Data
Sequence Alignment
Species Specificity
Spectrometry, Fluorescence
Two-Hybrid System Techniques
Adenosine Triphosphatases metabolism
Adenylate Kinase metabolism
Models, Molecular
Protein Conformation
Pyrococcus horikoshii enzymology
Ribosomal Proteins metabolism
Ribosome Subunits, Small physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 110
- Issue :
- 38
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 24003121
- Full Text :
- https://doi.org/10.1073/pnas.1306389110