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Some examples of how NMR can provide information about biological systems

Some examples of how NMR can provide information about biological systems. Autoinhibited Multi-Domain Proteins are Critical in Many Signal Transduction Pathways. Numerous multi-domain proteins transmit signals from the T-cell receptor. Rosen lab.

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Some examples of how NMR can provide information about biological systems

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  1. Some examples of how NMR can provide information about biological systems

  2. Autoinhibited Multi-Domain Proteins are Critical in Many Signal Transduction Pathways • Numerous multi-domain • proteins transmit signals • from the T-cell receptor Rosen lab

  3. Vav proto-oncoprotein is a key GEF that regulates Rho family GTPases • A member of the Dbl family of guanine nucleotide exchange factors (GEF) for the Rho family of GTP binding proteins. • Important in hematopoiesis, playing a role in T-cell and B-cell development and activation. • DH domain is inhibited by contacts with the Acidic (Ac) region and is relieved by phosphorylation of the Ac region tyrosines

  4. A Helix From the Ac Domain Binds in the DH Active Site: Autoinhibition by Occlusion • Y3 is buried in the interface Aghazadeh, et al. Cell, 102: 625-633.

  5. Phosphorylation Disrupts Autoinhibitory Interactions Aghazadeh, et al. Cell, 102: 625-633. • Amide resonances from N-terminal (Ac region) helix collapse to the center of • the 1H/15N HSQC spectra and become extremely intense • 13Ca and 13Cb assignments indicate that the N-terminus is random coil

  6. How is Y3 Accessed by Kinases? A general problem in autoinhibition/allostery: activators must contact buried sites ?

  7. Linearity of chemical • shifts across multiple • perturbations indicates • a two-state equilibrium Chemical Shift Can Report on Population Distribution closed 50:50 mixture open wobs = powo + (1-po)wc

  8. Mutants Sample a Range of Population Distributions Open Closed • Linearity strongly suggests an • equilibrium between Y3- • bound and Y3-unbound states wobs = powo + (1-po)wc Conformational equilibrium controls Vav activation by Src family kinases

  9. Vav WASP/Cdc42 Science. 1998 Jan 23;279(5350):509-14. Nature. 2000 Mar 9;404(6774):151-8. Nature. 1999 May 27;399(6734):379-83. Rosen lab

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