Conformational Flexibility of Proteins Involved in Ribosome Biogenesis: Investigations via Small Angle X-ray Scattering (SAXS)

DOI: 10.3390/cryst8030109

Authors: Dritan Siliqi (Istituto di Cristallografia, Consiglio Nazionale delle Ricerche) , James Foadi (Diamond Light Source) , Marco Mazzorana (Diamond Light Source) , Davide Altamura (Istituto di Cristallografia, Consiglio Nazionale delle Ricerche) , Alfonso Méndez-godoy (Universidad Nacional Autónoma de México) , Nuria Sánchez-puig (Universidad Nacional Autónoma de México)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Crystals , VOL 8

State: Published (Approved)
Published: February 2018
Diamond Proposal Number(s): 11690 , 14029 , 16970

Abstract: The dynamism of proteins is central to their function, and several proteins have been described as flexible, as consisting of multiple domains joined by flexible linkers, and even as intrinsically disordered. Several techniques exist to study protein structures, but small angle X-ray scattering (SAXS) has proven to be particularly powerful for the quantitative analysis of such flexible systems. In the present report, we have used SAXS in combination with X-ray crystallography to highlight their usefulness at characterizing flexible proteins, using as examples two proteins involved in different steps of ribosome biogenesis. The yeast BRCA2 and CDKN1A-interactig protein, Bcp1, is a chaperone for Rpl23 of unknown structure. We showed that it consists of a rigid, slightly elongated protein, with a secondary structure comprising a mixture of alpha helices and beta sheets. As an example of a flexible molecule, we studied the SBDS (Shwachman-Bodian-Diamond Syndrome) protein that is involved in the cytoplasmic maturation of the 60S subunit and constitutes the mutated target in the Shwachman-Diamond Syndrome. In solution, this protein coexists in an ensemble of three main conformations, with the N- and C-terminal ends adopting different orientations with respect to the central domain. The structure observed in the protein crystal corresponds to an average of those predicted by the SAXS flexibility analysis.

Journal Keywords: SAXS; Bcp1; SBDS; flexibility

Subject Areas: Technique Development, Biology and Bio-materials


Instruments: B21-High Throughput SAXS , I24-Microfocus Macromolecular Crystallography

Documents:
crystals-08-00109.pdf

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