http://www.bibsonomy.org/burst/user/mikromolbio/Genetic_VectorsBibSonomy BuRST Feed for /user/mikromolbio/Genetic_Vectors2008-07-26T21:34:46+02:00http://www.bibsonomy.org/bibtex/2dca52bc2607846f74bf0d7984035d738/mikromolbiomikromolbio2008-05-07T15:52:44+02:00Post-Translational Ligands Archaeal_Proteins Ribonucleases Nucleic_Acid_Conformation RNA-Binding_Proteins Eukaryotic_Cells Lysine IFZ RNA Genetic_Vectors Nucleic_Acid Messenger Base_Sequence Halobacterium Archaeal Cells Amino_Acid_Sequence Sequence_Homology Protein_Processing Molecular_Sequence_Data Peptide_Initiation_Factors Cultured <span style="color:#555555;">Steffen <a href="http://www.bibsonomy.org/author/Wagner">Wagner</a> and Gabriele <a href="http://www.bibsonomy.org/author/Klug">Klug</a> </span><em>The Journal of biological chemistry</em><em>May2007. </em><em>PMID: 17369252 . </em>Wed May 07 15:52:44 CEST 2008The Journal of biological chemistryMayPMID: 1736925213966-76An archaeal protein with homology to the eukaryotic translation initiation factor 5A shows ribonucleolytic activity2822007Post-Translational Ligands Archaeal_Proteins Ribonucleases Nucleic_Acid_Conformation RNA-Binding_Proteins Eukaryotic_Cells Lysine IFZ RNA Genetic_Vectors Nucleic_Acid Messenger Base_Sequence Halobacterium Archaeal Cells Amino_Acid_Sequence Sequence_Homology Protein_Processing Molecular_Sequence_Data Peptide_Initiation_Factors Cultured To identify proteins that are involved in RNA degradation and processing in Halobacterium sp. NRC-1, we purified proteins with RNA-degrading activity by classical biochemical techniques. One of these proteins showed strong homology to the eukaryotic initiation factor 5A (eIF-5A) and was accordingly named archaeal initiation factor 5A (aIF-5A). Eukaryotic IF-5A is known to be involved in mRNA turnover and to bind RNA. Hypusination of eIF-5A is required for sequence-specific binding of RNA. This unique post-translational modification is restricted to Eukarya and Archaea. The exact function of eIF-5A in RNA turnover remained obscure. Here we show for the first time that aIF-5A from Halobacterium sp. NRC-1 exhibits RNA cleavage activity, preferentially cleaving adjacent to A nucleotides. Detectable RNA binding could be shown for aIF-5A purified from Halobacterium sp. NRC-1 but not from Escherichia coli, while both proteins possess RNA cleavage activity, indicating that hypusination of aIF-5A is required for RNA binding but not for its RNA cleavage activity. Furthermore, we show that the hypusinated form of eIF-5A also shows RNase activity while the unmodified protein does not. Charged amino acids in the N-terminal domain of aIF-5A as well as in the C-terminal domain, which is highly similar to the cold shock protein A (CspA), an RNA chaperone of E. coli, are important for RNA cleavage activity. Moreover our results reveal that activity of aIF-5A depends on its oligomeric state.