1jcd
From Proteopedia
Crystal Structure of a Novel Alanine-Zipper Trimer at 1.3 A Resolution, I6A,L9A,V13A,L16A,V20A,L23A,V27A,M30A,V34A,L48A,M51A mutations
Overview
A major challenge in protein folding is to identify and quantify specific structural determinants that allow native proteins to acquire their unique folded structures. Here we report the engineering of a 52-residue protein (Ala-14) that contains exclusively alanine residues at the hydrophobic a and d positions of a natural heptad-repeat sequence. Ala-14 is unfolded under normal solution conditions yet forms a parallel three-stranded alpha-helical coiled coil in crystals. Ala-14 trimers in the solid state associate with each other through the pairing of polar side chains and formation of an extended network of water-mediated hydrogen bonds. In contrast to the classical view that local intramolecular tertiary interactions dictate the three-dimensional structure of small single-domain proteins, Ala-14 shows that long range intermolecular interactions can be essential in determining the metastable alanine-zipper structure. A similar interplay between short range local and longer range global forces may underlie the conformational properties of the growing class of natively unstructured proteins in biological processes.
About this Structure
1JCD is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
An alanine-zipper structure determined by long range intermolecular interactions., Liu J, Lu M, J Biol Chem. 2002 Dec 13;277(50):48708-13. Epub 2002 Oct 3. PMID:12368282 Page seeded by OCA on Fri May 2 21:02:55 2008
