Journalartikel

Jahr der Veröffentlichung: 2007

Seiten: 13966-13976

Zeitschrift: Journal of Biological Chemistry

Bandnummer: 282

Heftnummer: 19

ISSN: 0021-9258

Open Access Status: Hybrid

DOI Link: https://doi.org/10.1074/jbc.M701166200

Verlag: Elsevier

Abstract: 
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.

Harvard-Zitierstil: Wagner, S. and Klug, G. (2007) An archaeal protein with homology to the eukaryotic translation initiation factor 5A shows ribonucleolytic activity, Journal of Biological Chemistry, 282(19), pp. 13966-13976. https://doi.org/10.1074/jbc.M701166200

APA-Zitierstil: Wagner, S., & Klug, G. (2007). An archaeal protein with homology to the eukaryotic translation initiation factor 5A shows ribonucleolytic activity. Journal of Biological Chemistry. 282(19), 13966-13976. https://doi.org/10.1074/jbc.M701166200