Structural and dynamic characterization of intrinsically disordered human securin by NMR spectroscopy.

TitleStructural and dynamic characterization of intrinsically disordered human securin by NMR spectroscopy.
Publication TypeJournal Article
Year of Publication2008
AuthorsCsizmok, V., I. C. Felli, P. Tompa, L. Banci, and I. Bertini
JournalJ Am Chem Soc
Volume130
Issue50
Pagination16873-9
Date Published2008 Dec 17
Type of Articleidp
ISSN1520-5126
KeywordsAlgorithms, Cell Cycle Proteins, Endopeptidases, Humans, Neoplasm Proteins, Nuclear Magnetic Resonance, Biomolecular
Abstract

Understanding the molecular action of securin, the inhibitor of separase in mitosis, is of immense theoretical and biomedical importance. The residue-level structural description of an intrinsically disordered protein of this length (202 amino acids, containing 24 prolines), however, represents a particular challenge. Here we combined (1)H-detected and (13)C-detected protonless NMR experiments to achieve full assignment of securin's backbone amide resonances. Chemical shifts, (15)N relaxation rates (R(1), R(2), (1)H-(15)N NOEs), (1)H exchange rates with the solvent (CLEANEX-PM), and (1)H-(15)N residual dipolar couplings were determined along the entire length of the protein. This analysis showed that securin is not entirely disordered, but segregates into a largely disordered N-terminal half and a C-terminal half with transient segmental order, within which the segment D(150)-F(159) has a significant helical tendency and segments E(113)-S(127) and W(174)-L(178) also show a significant deviation from random-coil behavior. These results, in combination with bioinformatic and biochemical data on the securin/separase interaction, shed light on the inhibitory action of securin on separase.

DOI10.1021/ja805510b
Alternate JournalJ. Am. Chem. Soc.
PubMed ID19053469
Grant ListISRF 067595 / / Wellcome Trust / United Kingdom