Stereospecific assignments in proteins using exact NOEs

Author(s)
J. Orts, B. Vogeli, R. Riek, P. Guntert
Abstract

Recently developed methods to measure distances in proteins with high accuracy by “exact” nuclear Overhauser effects (eNOEs) make it possible to determine stereospecific assignments, which are particularly important to fully exploit the accuracy of the eNOE distance measurements. Stereospecific assignments are determined by comparing the eNOE-derived distances to protein structure bundles calculated without stereospecific assignments, or an independently determined crystal structure. The absolute and relative CYANA target function difference upon swapping the stereospecific assignment of a diastereotopic group yields the respective stereospecific assignment. We applied the method to the eNOE data set that has recently been obtained for the third immunoglobulin-binding domain of protein G (GB3). The 884 eNOEs provide relevant data for 47 of the total of 75 diastereotopic groups. Stereospecific assignments could be established for 45 diastereotopic groups (96 %) using the X-ray structure, or for 27 diastereotopic groups (57 %) using structures calculated with the eNOE data set without stereospecific assignments, all of which are in agreement with those determined previously. The latter case is relevant for structure determinations based on eNOEs. The accuracy of the eNOE distance measurements is crucial for making stereospecific assignments because applying the same method to the traditional NOE data set for GB3 with imprecise upper distance bounds yields only 13 correct stereospecific assignments using the X-ray structure or 2 correct stereospecific assignments using NMR structures calculated without stereospecific assignments.

Organisation(s)
External organisation(s)
Eidgenössische Technische Hochschule Zürich, Johann Wolfgang Goethe-Universität Frankfurt am Main, Tokyo Metropolitan University
Journal
Journal of Biomolecular NMR
Volume
57
Pages
211-218
No. of pages
8
ISSN
0925-2738
DOI
https://doi.org/10.1007/s10858-013-9780-4
Publication date
2013
Peer reviewed
Yes
Austrian Fields of Science 2012
106002 Biochemistry, 106006 Biophysics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/a56a2b48-a77f-4082-80e0-01327d3a7ddf