1. Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, and Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany

Correspondence to: Hartmut Oschkinat Correspondence and requests for materials should be addressed to H.O. (e-mail: Email: oschkinat@fmp-berlin.de) or B.v.R. (Email: brossum@fmp-berlin.de).

Abstract

The determination of a representative set of protein structures is a chief aim in structural genomics. Solid-state NMR may have a crucial role in structural investigations of those proteins that do not easily form crystals or are not accessible to solution NMR, such as amyloid systems¹ or membrane proteins^{2, 3, 4}. Here we present a protein structure determined by solid-state magic-angle-spinning (MAS) NMR. Almost complete ¹³C and ¹⁵N resonance assignments for a micro-crystalline preparation of the -spectrin Src-homology 3 (SH3) domain⁵ formed the basis for the extraction of a set of distance restraints. These restraints were derived from proton-driven spin diffusion (PDSD) spectra of biosynthetically site-directed, labelled samples obtained from bacteria grown using [1,3-¹³C]glycerol or [2-¹³C]glycerol as carbon sources. This allowed the observation of long-range distance correlations up to 7 Å. The calculated global fold of the -spectrin SH3 domain is based on 286 inter-residue ¹³C–¹³C and six ¹⁵N–¹⁵N restraints, all self-consistently obtained by solid-state MAS NMR. This MAS NMR procedure should be widely applicable to small membrane proteins that can be expressed in bacteria.