1y66

Publication Abstract from PubMed

Our goal was to compute a stable, full-sequence design of the Drosophila melanogaster engrailed homeodomain. Thermal and chemical denaturation data indicated the design was significantly more stable than was the wild-type protein. The data were also nearly identical to those for a similar, later full-sequence design, which was shown by NMR to adopt the homeodomain fold: a three-helix, globular monomer. However, a 1.65 A crystal structure of the design described here turned out to be of a completely different fold: a four-helix, rodlike tetramer. The crystallization conditions included approximately 25% dioxane, and subsequent experiments by circular dichroism and sedimentation velocity analytical ultracentrifugation indicated that dioxane increases the helicity and oligomerization state of the designed protein. We attribute at least part of the discrepancy between the target fold and the crystal structure to the presence of a high concentration of dioxane.

Dioxane contributes to the altered conformation and oligomerization state of a designed engrailed homeodomain variant.,Hom GK, Lassila JK, Thomas LM, Mayo SL Protein Sci. 2005 Apr;14(4):1115-9. Epub 2005 Mar 1. PMID:15741348^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.