HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article OPEN ACCESS ARTICLE Full Text Full Text (PDF) All Versions of this Article: rna.671807v1 13/12/2053    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Rajkowitsch, L. Articles by Schroeder, R. Search for Related Content PubMed PubMed Citation Articles by Rajkowitsch, L. Articles by Schroeder, R. Social Bookmarking                   What's this?

Dissecting RNA chaperone activity

Max F. Perutz Laboratories, University of Vienna, A-1030 Vienna, Austria

Many RNA-binding proteins help RNAs to fold via their RNA chaperone activity. This term has been used widely without accounting for the diversity of the observed reactions, which include complex events like restructuring of misfolded catalytic RNAs, promoting the assembly of RNA-protein complexes, and mediating RNA–RNA interactions. Proteins display very diverse activities depending on the assays used to measure RNA chaperone activity. To classify proteins with this activity, we compared three exemplary proteins from E. coli, host factor Hfq, ribosomal protein S1, and the histone-like protein StpA for their abilities to promote two simple reactions, RNA annealing and strand displacement. The results of a FRET-based assay show that S1 promotes only RNA strand displacement while Hfq solely enhances RNA annealing. StpA, in contrast, is active in both reactions. To test whether the two activities can be assigned to different domains of the bipartite-structured StpA, we assayed the purified N- and C- terminal domains separately. While both domains are unable to promote RNA annealing, we can attribute the RNA strand displacement activity of StpA to the C-terminal domain. Correlating with their RNA annealing activities, only Hfq and full-length StpA display simultaneous binding of two RNAs, suggesting a matchmaker-like model for this activity. For StpA, this "RNA crowding" requires protein–protein interactions, since a dimerization-deficient StpA mutant lost the ability to bind and anneal two RNAs. These results underline the difference between the two reaction types, making it necessary to distinguish and classify proteins according to their specific RNA chaperone activities.

Keywords: Hfq; S1; StpA dimerization; FRET; RNA annealing; strand displacement

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. Kuciak, C. Gabus, R. Ivanyi-Nagy, K. Semrad, R. Storchak, O. Chaloin, S. Muller, Y. Mely, and J.-L. Darlix The HIV-1 transcriptional activator Tat has potent nucleic acid chaperoning activities in vitro Nucleic Acids Res., June 1, 2008; 36(10): 3389 - 3400. [Abstract] [Full Text] [PDF]

				P. Aliprandi, C. Sizun, J. Perez, F. Mareuil, S. Caputo, J.-L. Leroy, B. Odaert, S. Laalami, M. Uzan, and F. Bontems S1 Ribosomal Protein Functions in Translation Initiation and Ribonuclease RegB Activation Are Mediated by Similar RNA-Protein Interactions: AN NMR AND SAXS ANALYSIS J. Biol. Chem., May 9, 2008; 283(19): 13289 - 13301. [Abstract] [Full Text] [PDF]