The C Terminus of the Ribosomal-Associated Protein LrtA Is an Intrinsically Disordered Oligomer

The 191-residue-long LrtA protein of <i>Synechocystis</i> sp. PCC 6803 is involved in post-stress survival and in stabilizing 70S ribosomal particles. It belongs to the hibernating promoting factor (HPF) family, intervening in protein synthesis. The protein consists of two domains: The N...

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Bibliographic Details
Main Authors: José L. Neira, A. Marcela Giudici, Felipe Hornos, Arantxa Arbe, Bruno Rizzuti
Format: Article
Language:English
Published: MDPI AG 2018-12-01
Series:International Journal of Molecular Sciences
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Online Access:https://www.mdpi.com/1422-0067/19/12/3902
Description
Summary:The 191-residue-long LrtA protein of <i>Synechocystis</i> sp. PCC 6803 is involved in post-stress survival and in stabilizing 70S ribosomal particles. It belongs to the hibernating promoting factor (HPF) family, intervening in protein synthesis. The protein consists of two domains: The N-terminal region (N-LrtA, residues 1&#8315;101), which is common to all the members of the HPF, and seems to be well-folded; and the C-terminal region (C-LrtA, residues 102&#8315;191), which is hypothesized to be disordered. In this work, we studied the conformational preferences of isolated C-LrtA in solution. The protein was disordered, as shown by computational modelling, 1D-<sup>1</sup>H NMR, steady-state far-UV circular dichroism (CD) and chemical and thermal denaturations followed by fluorescence and far-UV CD. Moreover, at physiological conditions, as indicated by several biochemical and hydrodynamic techniques, isolated C-LrtA intervened in a self-association equilibrium, involving several oligomerization reactions. Thus, C-LrtA was an oligomeric disordered protein.
ISSN:1422-0067