1ik7
From Proteopedia
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Crystal Structure of the Uncomplexed Pelle Death Domain
Overview
The death domain (DD) of the protein kinase Pelle adopts a six-helix, bundle fold in the crystal structure of the complex with its dimerization, partner, Tube-DD. However, in crystals obtained from a solution of 45%, 2-methyl-2,4-pentanediol (MPD), the C-terminal half of Pelle-DD folds into, a single helix, and the N-terminal half of the molecule is disordered. The, helical segment forms an antiparallel dimer with the corresponding helix, of a symmetry-related molecule, and together they form extensive lattice, interactions similar in number, composition, and buried surface to those, in the six-helix bundle of the native fold. Secondary structure analysis, by heteronuclear nuclear magnetic resonance spectroscopy (NMR), demonstrates that Pelle-DD adopts a six-helix bundle fold in aqueous, solution. The fold is perturbed by MPD, with the largest chemical shift, changes in one helix and two loop regions that encompass the Tube-DD, binding site. Pelle-DD is stable to urea denaturation with a folding free, energy of 7.9 kcal/mol at 25 degrees C but is destabilized, with loss of, urea binding sites, in the presence of MPD. The data are consistent with a, cosolvent denaturation model in which MPD denatures the N terminus of, Pelle-DD but induces the C terminus to form a more compact structure and, aggregate. A similar perturbation in vivo might occur at the plasma, membrane and could have consequences for Pelle-mediated regulation., Generally, crystallographers should be aware that high concentrations of, MPD or related cosolvents can alter the tertiary structure of susceptible, proteins.
About this Structure
1IK7 is a Single protein structure of sequence from Drosophila melanogaster with TRS and MPD as ligands. Active as Non-specific serine/threonine protein kinase, with EC number 2.7.11.1 Full crystallographic information is available from OCA.
Reference
Cosolvent-induced transformation of a death domain tertiary structure., Xiao T, Gardner KH, Sprang SR, Proc Natl Acad Sci U S A. 2002 Aug 20;99(17):11151-6. Epub 2002 Aug 12. PMID:12177432
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