NMR Research Today is a free monthly online journal that collates and summarizes the latest research about NMR, including details on nuclear magnetic resonance, structural determination, techniques.

NMR analyses of the activation of the Arp2/3 complex by neuronal Wiskott-Aldrich syndrome protein.

Kreishman-Deitrick M, Goley ED, Burdine L, Denison C, Egile C, Li R, Murali N, Kodadek TJ, Welch MD, Rosen MK

Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.

The VCA domain of the neuronal Wiskott-Aldrich syndrome protein (N-WASP) is a potent activator of the Arp2/3 complex, a 240 kDa heteroheptameric actin-nucleating assembly. We used site-directed spin labeling of N-WASP peptides in conjunction with methyl-TROSY spectra of the intact, selectively labeled Arp2/3 complex to identify regions of the VCA that are proximal to the ARPC3 subunit of the assembly. We also cross-linked CA peptides to the Arp3, Arp2, ARPC1, and ARPC3 subunits. The combined data suggest that the extreme C-terminus of the A region and the C-terminus of the C region of N-WASP are proximal to ARPC3. These results have implications for the mechanism of Arp2/3 complex activation by VCA peptides. This study also demonstrates the utility of NMR spectroscopy for studying ligand binding events in large, asymmetric, macromolecular assemblies.

Published 15 November 2005 in Biochemistry, 44(46): 15247-56.
Full-text of this article is available online (may require subscription).

© 2005-2008 NMR Research Today. All Rights Reserved.